+package SQL::Abstract; # see doc at end of file
-package SQL::Abstract;
+# LDNOTE : this code is heavy refactoring from original SQLA.
+# Several design decisions will need discussion during
+# the test / diffusion / acceptance phase; those are marked with flag
+# 'LDNOTE' (note by laurent.dami AT free.fr)
+
+use Carp;
+use strict;
+use warnings;
+use List::Util qw/first/;
+use Scalar::Util qw/blessed/;
+
+#======================================================================
+# GLOBALS
+#======================================================================
+
+our $VERSION = '1.52';
+
+# This would confuse some packagers
+#$VERSION = eval $VERSION; # numify for warning-free dev releases
+
+our $AUTOLOAD;
+
+# special operators (-in, -between). May be extended/overridden by user.
+# See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
+my @BUILTIN_SPECIAL_OPS = (
+ {regex => qr/^(not )?between$/i, handler => \&_where_field_BETWEEN},
+ {regex => qr/^(not )?in$/i, handler => \&_where_field_IN},
+);
+
+#======================================================================
+# DEBUGGING AND ERROR REPORTING
+#======================================================================
+
+sub _debug {
+ return unless $_[0]->{debug}; shift; # a little faster
+ my $func = (caller(1))[3];
+ warn "[$func] ", @_, "\n";
+}
+
+sub belch (@) {
+ my($func) = (caller(1))[3];
+ carp "[$func] Warning: ", @_;
+}
+
+sub puke (@) {
+ my($func) = (caller(1))[3];
+ croak "[$func] Fatal: ", @_;
+}
+
+
+#======================================================================
+# NEW
+#======================================================================
+
+sub new {
+ my $self = shift;
+ my $class = ref($self) || $self;
+ my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
+
+ # choose our case by keeping an option around
+ delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
+
+ # default logic for interpreting arrayrefs
+ $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
+
+ # how to return bind vars
+ # LDNOTE: changed nwiger code : why this 'delete' ??
+ # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
+ $opt{bindtype} ||= 'normal';
+
+ # default comparison is "=", but can be overridden
+ $opt{cmp} ||= '=';
+
+ # try to recognize which are the 'equality' and 'unequality' ops
+ # (temporary quickfix, should go through a more seasoned API)
+ $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
+ $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
+
+ # SQL booleans
+ $opt{sqltrue} ||= '1=1';
+ $opt{sqlfalse} ||= '0=1';
+
+ # special operators
+ $opt{special_ops} ||= [];
+ push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
+
+ return bless \%opt, $class;
+}
+
+
+
+#======================================================================
+# INSERT methods
+#======================================================================
+
+sub insert {
+ my $self = shift;
+ my $table = $self->_table(shift);
+ my $data = shift || return;
+
+ my $method = $self->_METHOD_FOR_refkind("_insert", $data);
+ my ($sql, @bind) = $self->$method($data);
+ $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
+ return wantarray ? ($sql, @bind) : $sql;
+}
+
+sub _insert_HASHREF { # explicit list of fields and then values
+ my ($self, $data) = @_;
+
+ my @fields = sort keys %$data;
+
+ my ($sql, @bind) = $self->_insert_values($data);
+
+ # assemble SQL
+ $_ = $self->_quote($_) foreach @fields;
+ $sql = "( ".join(", ", @fields).") ".$sql;
+
+ return ($sql, @bind);
+}
+
+sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
+ my ($self, $data) = @_;
+
+ # no names (arrayref) so can't generate bindtype
+ $self->{bindtype} ne 'columns'
+ or belch "can't do 'columns' bindtype when called with arrayref";
+
+ # fold the list of values into a hash of column name - value pairs
+ # (where the column names are artificially generated, and their
+ # lexicographical ordering keep the ordering of the original list)
+ my $i = "a"; # incremented values will be in lexicographical order
+ my $data_in_hash = { map { ($i++ => $_) } @$data };
+
+ return $self->_insert_values($data_in_hash);
+}
+
+sub _insert_ARRAYREFREF { # literal SQL with bind
+ my ($self, $data) = @_;
+
+ my ($sql, @bind) = @${$data};
+ $self->_assert_bindval_matches_bindtype(@bind);
+
+ return ($sql, @bind);
+}
+
+
+sub _insert_SCALARREF { # literal SQL without bind
+ my ($self, $data) = @_;
+
+ return ($$data);
+}
+
+sub _insert_values {
+ my ($self, $data) = @_;
+
+ my (@values, @all_bind);
+ foreach my $column (sort keys %$data) {
+ my $v = $data->{$column};
+
+ $self->_SWITCH_refkind($v, {
+
+ ARRAYREF => sub {
+ if ($self->{array_datatypes}) { # if array datatype are activated
+ push @values, '?';
+ push @all_bind, $self->_bindtype($column, $v);
+ }
+ else { # else literal SQL with bind
+ my ($sql, @bind) = @$v;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @values, $sql;
+ push @all_bind, @bind;
+ }
+ },
+
+ ARRAYREFREF => sub { # literal SQL with bind
+ my ($sql, @bind) = @${$v};
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @values, $sql;
+ push @all_bind, @bind;
+ },
+
+ # THINK : anything useful to do with a HASHREF ?
+ HASHREF => sub { # (nothing, but old SQLA passed it through)
+ #TODO in SQLA >= 2.0 it will die instead
+ belch "HASH ref as bind value in insert is not supported";
+ push @values, '?';
+ push @all_bind, $self->_bindtype($column, $v);
+ },
+
+ SCALARREF => sub { # literal SQL without bind
+ push @values, $$v;
+ },
+
+ SCALAR_or_UNDEF => sub {
+ push @values, '?';
+ push @all_bind, $self->_bindtype($column, $v);
+ },
+
+ });
+
+ }
+
+ my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
+ return ($sql, @all_bind);
+}
+
+
+
+#======================================================================
+# UPDATE methods
+#======================================================================
+
+
+sub update {
+ my $self = shift;
+ my $table = $self->_table(shift);
+ my $data = shift || return;
+ my $where = shift;
+
+ # first build the 'SET' part of the sql statement
+ my (@set, @all_bind);
+ puke "Unsupported data type specified to \$sql->update"
+ unless ref $data eq 'HASH';
+
+ for my $k (sort keys %$data) {
+ my $v = $data->{$k};
+ my $r = ref $v;
+ my $label = $self->_quote($k);
+
+ $self->_SWITCH_refkind($v, {
+ ARRAYREF => sub {
+ if ($self->{array_datatypes}) { # array datatype
+ push @set, "$label = ?";
+ push @all_bind, $self->_bindtype($k, $v);
+ }
+ else { # literal SQL with bind
+ my ($sql, @bind) = @$v;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @set, "$label = $sql";
+ push @all_bind, @bind;
+ }
+ },
+ ARRAYREFREF => sub { # literal SQL with bind
+ my ($sql, @bind) = @${$v};
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @set, "$label = $sql";
+ push @all_bind, @bind;
+ },
+ SCALARREF => sub { # literal SQL without bind
+ push @set, "$label = $$v";
+ },
+ SCALAR_or_UNDEF => sub {
+ push @set, "$label = ?";
+ push @all_bind, $self->_bindtype($k, $v);
+ },
+ });
+ }
+
+ # generate sql
+ my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
+ . join ', ', @set;
+
+ if ($where) {
+ my($where_sql, @where_bind) = $self->where($where);
+ $sql .= $where_sql;
+ push @all_bind, @where_bind;
+ }
+
+ return wantarray ? ($sql, @all_bind) : $sql;
+}
+
+
+
+
+#======================================================================
+# SELECT
+#======================================================================
+
+
+sub select {
+ my $self = shift;
+ my $table = $self->_table(shift);
+ my $fields = shift || '*';
+ my $where = shift;
+ my $order = shift;
+
+ my($where_sql, @bind) = $self->where($where, $order);
+
+ my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
+ : $fields;
+ my $sql = join(' ', $self->_sqlcase('select'), $f,
+ $self->_sqlcase('from'), $table)
+ . $where_sql;
+
+ return wantarray ? ($sql, @bind) : $sql;
+}
+
+#======================================================================
+# DELETE
+#======================================================================
+
+
+sub delete {
+ my $self = shift;
+ my $table = $self->_table(shift);
+ my $where = shift;
+
+
+ my($where_sql, @bind) = $self->where($where);
+ my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
+
+ return wantarray ? ($sql, @bind) : $sql;
+}
+
+
+#======================================================================
+# WHERE: entry point
+#======================================================================
+
+
+
+# Finally, a separate routine just to handle WHERE clauses
+sub where {
+ my ($self, $where, $order) = @_;
+
+ # where ?
+ my ($sql, @bind) = $self->_recurse_where($where);
+ $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
+
+ # order by?
+ if ($order) {
+ $sql .= $self->_order_by($order);
+ }
+
+ return wantarray ? ($sql, @bind) : $sql;
+}
+
+
+sub _recurse_where {
+ my ($self, $where, $logic) = @_;
+
+ # dispatch on appropriate method according to refkind of $where
+ my $method = $self->_METHOD_FOR_refkind("_where", $where);
+
+
+ my ($sql, @bind) = $self->$method($where, $logic);
+
+ # DBIx::Class directly calls _recurse_where in scalar context, so
+ # we must implement it, even if not in the official API
+ return wantarray ? ($sql, @bind) : $sql;
+}
+
+
+
+#======================================================================
+# WHERE: top-level ARRAYREF
+#======================================================================
+
+
+sub _where_ARRAYREF {
+ my ($self, $where, $logic) = @_;
+
+ $logic = uc($logic || $self->{logic});
+ $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
+
+ my @clauses = @$where;
+
+ my (@sql_clauses, @all_bind);
+ # need to use while() so can shift() for pairs
+ while (my $el = shift @clauses) {
+
+ # switch according to kind of $el and get corresponding ($sql, @bind)
+ my ($sql, @bind) = $self->_SWITCH_refkind($el, {
+
+ # skip empty elements, otherwise get invalid trailing AND stuff
+ ARRAYREF => sub {$self->_recurse_where($el) if @$el},
+
+ ARRAYREFREF => sub { @{${$el}} if @{${$el}}},
+
+ HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
+ # LDNOTE : previous SQLA code for hashrefs was creating a dirty
+ # side-effect: the first hashref within an array would change
+ # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
+ # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
+ # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
+
+ SCALARREF => sub { ($$el); },
+
+ SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
+ $self->_recurse_where({$el => shift(@clauses)})},
+
+ UNDEF => sub {puke "not supported : UNDEF in arrayref" },
+ });
+
+ if ($sql) {
+ push @sql_clauses, $sql;
+ push @all_bind, @bind;
+ }
+ }
+
+ return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
+}
+
+#======================================================================
+# WHERE: top-level ARRAYREFREF
+#======================================================================
+
+sub _where_ARRAYREFREF {
+ my ($self, $where) = @_;
+ my ($sql, @bind) = @{${$where}};
+
+ return ($sql, @bind);
+}
+
+#======================================================================
+# WHERE: top-level HASHREF
+#======================================================================
+
+sub _where_HASHREF {
+ my ($self, $where) = @_;
+ my (@sql_clauses, @all_bind);
+
+ # LDNOTE : don't really know why we need to sort keys
+ for my $k (sort keys %$where) {
+ my $v = $where->{$k};
+
+ # ($k => $v) is either a special op or a regular hashpair
+ my ($sql, @bind) = ($k =~ /^-(.+)/) ? $self->_where_op_in_hash($1, $v)
+ : do {
+ my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
+ $self->$method($k, $v);
+ };
+
+ push @sql_clauses, $sql;
+ push @all_bind, @bind;
+ }
+
+ return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
+}
+
+
+sub _where_op_in_hash {
+ my ($self, $op_str, $v) = @_;
+
+ $op_str =~ /^ (AND|OR|NEST) ( \_? \d* ) $/xi
+ or puke "unknown operator: -$op_str";
+
+ my $op = uc($1); # uppercase, remove trailing digits
+ if ($2) {
+ belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
+ . "You probably wanted ...-and => [ $op_str => COND1, $op_str => COND2 ... ]";
+ }
+
+ $self->_debug("OP(-$op) within hashref, recursing...");
+
+ $self->_SWITCH_refkind($v, {
+
+ ARRAYREF => sub {
+ return $self->_where_ARRAYREF($v, $op eq 'NEST' ? '' : $op);
+ },
+
+ HASHREF => sub {
+ if ($op eq 'OR') {
+ return $self->_where_ARRAYREF([%$v], 'OR');
+ }
+ else { # NEST | AND
+ return $self->_where_HASHREF($v);
+ }
+ },
+
+ SCALARREF => sub { # literal SQL
+ $op eq 'NEST'
+ or puke "-$op => \\\$scalar not supported, use -nest => ...";
+ return ($$v);
+ },
+
+ ARRAYREFREF => sub { # literal SQL
+ $op eq 'NEST'
+ or puke "-$op => \\[..] not supported, use -nest => ...";
+ return @{${$v}};
+ },
+
+ SCALAR => sub { # permissively interpreted as SQL
+ $op eq 'NEST'
+ or puke "-$op => 'scalar' not supported, use -nest => \\'scalar'";
+ belch "literal SQL should be -nest => \\'scalar' "
+ . "instead of -nest => 'scalar' ";
+ return ($v);
+ },
+
+ UNDEF => sub {
+ puke "-$op => undef not supported";
+ },
+ });
+}
+
+
+sub _where_hashpair_ARRAYREF {
+ my ($self, $k, $v) = @_;
+
+ if( @$v ) {
+ my @v = @$v; # need copy because of shift below
+ $self->_debug("ARRAY($k) means distribute over elements");
+
+ # put apart first element if it is an operator (-and, -or)
+ my $op = (
+ (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
+ ? shift @v
+ : ''
+ );
+ my @distributed = map { {$k => $_} } @v;
+
+ if ($op) {
+ $self->_debug("OP($op) reinjected into the distributed array");
+ unshift @distributed, $op;
+ }
+
+ my $logic = $op ? substr($op, 1) : '';
+
+ return $self->_recurse_where(\@distributed, $logic);
+ }
+ else {
+ # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
+ $self->_debug("empty ARRAY($k) means 0=1");
+ return ($self->{sqlfalse});
+ }
+}
+
+sub _where_hashpair_HASHREF {
+ my ($self, $k, $v, $logic) = @_;
+ $logic ||= 'and';
+
+ my ($all_sql, @all_bind);
+
+ for my $op (sort keys %$v) {
+ my $val = $v->{$op};
+
+ # put the operator in canonical form
+ $op =~ s/^-//; # remove initial dash
+ $op =~ tr/_/ /; # underscores become spaces
+ $op =~ s/^\s+//; # no initial space
+ $op =~ s/\s+$//; # no final space
+ $op =~ s/\s+/ /; # multiple spaces become one
+
+ my ($sql, @bind);
+
+ # CASE: special operators like -in or -between
+ my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
+ if ($special_op) {
+ ($sql, @bind) = $special_op->{handler}->($self, $k, $op, $val);
+ }
+ else {
+ $self->_SWITCH_refkind($val, {
+
+ ARRAYREF => sub { # CASE: col => {op => \@vals}
+ ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
+ },
+
+ SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
+ $sql = join ' ', $self->_convert($self->_quote($k)),
+ $self->_sqlcase($op),
+ $$val;
+ },
+
+ ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
+ my ($sub_sql, @sub_bind) = @$$val;
+ $self->_assert_bindval_matches_bindtype(@sub_bind);
+ $sql = join ' ', $self->_convert($self->_quote($k)),
+ $self->_sqlcase($op),
+ $sub_sql;
+ @bind = @sub_bind;
+ },
+
+ HASHREF => sub {
+ ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op);
+ },
+
+ UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
+ my $is = ($op =~ $self->{equality_op}) ? 'is' :
+ ($op =~ $self->{inequality_op}) ? 'is not' :
+ puke "unexpected operator '$op' with undef operand";
+ $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
+ },
+
+ FALLBACK => sub { # CASE: col => {op => $scalar}
+ $sql = join ' ', $self->_convert($self->_quote($k)),
+ $self->_sqlcase($op),
+ $self->_convert('?');
+ @bind = $self->_bindtype($k, $val);
+ },
+ });
+ }
+
+ ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
+ push @all_bind, @bind;
+ }
+ return ($all_sql, @all_bind);
+}
+
+
+
+sub _where_field_op_ARRAYREF {
+ my ($self, $k, $op, $vals) = @_;
+
+ if(@$vals) {
+ $self->_debug("ARRAY($vals) means multiple elements: [ @$vals ]");
+
+ # see if the first element is an -and/-or op
+ my $logic;
+ if ($vals->[0] =~ /^ - ( AND|OR ) $/ix) {
+ $logic = uc $1;
+ shift @$vals;
+ }
+
+ # distribute $op over each remaining member of @$vals, append logic if exists
+ return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
+
+ # LDNOTE : had planned to change the distribution logic when
+ # $op =~ $self->{inequality_op}, because of Morgan laws :
+ # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
+ # WHERE field != 22 OR field != 33 : the user probably means
+ # WHERE field != 22 AND field != 33.
+ # To do this, replace the above to roughly :
+ # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
+ # return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
+
+ }
+ else {
+ # try to DWIM on equality operators
+ # LDNOTE : not 100% sure this is the correct thing to do ...
+ return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
+ return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
+
+ # otherwise
+ puke "operator '$op' applied on an empty array (field '$k')";
+ }
+}
+
+
+sub _where_hashpair_SCALARREF {
+ my ($self, $k, $v) = @_;
+ $self->_debug("SCALAR($k) means literal SQL: $$v");
+ my $sql = $self->_quote($k) . " " . $$v;
+ return ($sql);
+}
+
+# literal SQL with bind
+sub _where_hashpair_ARRAYREFREF {
+ my ($self, $k, $v) = @_;
+ $self->_debug("REF($k) means literal SQL: @${$v}");
+ my ($sql, @bind) = @${$v};
+ $self->_assert_bindval_matches_bindtype(@bind);
+ $sql = $self->_quote($k) . " " . $sql;
+ return ($sql, @bind );
+}
+
+# literal SQL without bind
+sub _where_hashpair_SCALAR {
+ my ($self, $k, $v) = @_;
+ $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
+ my $sql = join ' ', $self->_convert($self->_quote($k)),
+ $self->_sqlcase($self->{cmp}),
+ $self->_convert('?');
+ my @bind = $self->_bindtype($k, $v);
+ return ( $sql, @bind);
+}
+
+
+sub _where_hashpair_UNDEF {
+ my ($self, $k, $v) = @_;
+ $self->_debug("UNDEF($k) means IS NULL");
+ my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
+ return ($sql);
+}
+
+#======================================================================
+# WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
+#======================================================================
+
+
+sub _where_SCALARREF {
+ my ($self, $where) = @_;
+
+ # literal sql
+ $self->_debug("SCALAR(*top) means literal SQL: $$where");
+ return ($$where);
+}
+
+
+sub _where_SCALAR {
+ my ($self, $where) = @_;
+
+ # literal sql
+ $self->_debug("NOREF(*top) means literal SQL: $where");
+ return ($where);
+}
+
+
+sub _where_UNDEF {
+ my ($self) = @_;
+ return ();
+}
+
+
+#======================================================================
+# WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
+#======================================================================
+
+
+sub _where_field_BETWEEN {
+ my ($self, $k, $op, $vals) = @_;
+
+ (ref $vals eq 'ARRAY' && @$vals == 2) or
+ (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3))
+ or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)";
+
+ my ($clause, @bind, $label, $and, $placeholder);
+ $label = $self->_convert($self->_quote($k));
+ $and = ' ' . $self->_sqlcase('and') . ' ';
+ $placeholder = $self->_convert('?');
+ $op = $self->_sqlcase($op);
+
+ if (ref $vals eq 'REF') {
+ ($clause, @bind) = @$$vals;
+ }
+ else {
+ my (@all_sql, @all_bind);
+
+ foreach my $val (@$vals) {
+ my ($sql, @bind) = $self->_SWITCH_refkind($val, {
+ SCALAR => sub {
+ return ($placeholder, ($val));
+ },
+ SCALARREF => sub {
+ return ($self->_convert($$val), ());
+ },
+ });
+ push @all_sql, $sql;
+ push @all_bind, @bind;
+ }
+
+ $clause = (join $and, @all_sql);
+ @bind = $self->_bindtype($k, @all_bind);
+ }
+ my $sql = "( $label $op $clause )";
+ return ($sql, @bind)
+}
+
+
+sub _where_field_IN {
+ my ($self, $k, $op, $vals) = @_;
+
+ # backwards compatibility : if scalar, force into an arrayref
+ $vals = [$vals] if defined $vals && ! ref $vals;
+
+ my ($label) = $self->_convert($self->_quote($k));
+ my ($placeholder) = $self->_convert('?');
+ $op = $self->_sqlcase($op);
+
+ my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
+ ARRAYREF => sub { # list of choices
+ if (@$vals) { # nonempty list
+ my $placeholders = join ", ", (($placeholder) x @$vals);
+ my $sql = "$label $op ( $placeholders )";
+ my @bind = $self->_bindtype($k, @$vals);
+
+ return ($sql, @bind);
+ }
+ else { # empty list : some databases won't understand "IN ()", so DWIM
+ my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
+ return ($sql);
+ }
+ },
+
+ ARRAYREFREF => sub { # literal SQL with bind
+ my ($sql, @bind) = @$$vals;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ return ("$label $op ( $sql )", @bind);
+ },
+
+ FALLBACK => sub {
+ puke "special op 'in' requires an arrayref (or arrayref-ref)";
+ },
+ });
+
+ return ($sql, @bind);
+}
+
+
+
+
+
+
+#======================================================================
+# ORDER BY
+#======================================================================
+
+sub _order_by {
+ my ($self, $arg) = @_;
+
+ # construct list of ordering instructions
+ my @order = $self->_SWITCH_refkind($arg, {
+
+ ARRAYREF => sub {
+ map {$self->_SWITCH_refkind($_, {
+ SCALAR => sub {$self->_quote($_)},
+ UNDEF => sub {},
+ SCALARREF => sub {$$_}, # literal SQL, no quoting
+ HASHREF => sub {$self->_order_by_hash($_)}
+ }) } @$arg;
+ },
+
+ SCALAR => sub {$self->_quote($arg)},
+ UNDEF => sub {},
+ SCALARREF => sub {$$arg}, # literal SQL, no quoting
+ HASHREF => sub {$self->_order_by_hash($arg)},
+
+ });
+
+ # build SQL
+ my $order = join ', ', @order;
+ return $order ? $self->_sqlcase(' order by')." $order" : '';
+}
+
+
+sub _order_by_hash {
+ my ($self, $hash) = @_;
+
+ # get first pair in hash
+ my ($key, $val) = each %$hash;
+
+ # check if one pair was found and no other pair in hash
+ $key && !(each %$hash)
+ or puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
+
+ my ($order) = ($key =~ /^-(desc|asc)/i)
+ or puke "invalid key in _order_by hash : $key";
+
+ $val = ref $val eq 'ARRAY' ? $val : [$val];
+ return join ', ', map { $self->_quote($_) . ' ' . $self->_sqlcase($order) } @$val;
+}
+
+
+
+#======================================================================
+# DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
+#======================================================================
+
+sub _table {
+ my $self = shift;
+ my $from = shift;
+ $self->_SWITCH_refkind($from, {
+ ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
+ SCALAR => sub {$self->_quote($from)},
+ SCALARREF => sub {$$from},
+ ARRAYREFREF => sub {join ', ', @$from;},
+ });
+}
+
+
+#======================================================================
+# UTILITY FUNCTIONS
+#======================================================================
+
+sub _quote {
+ my $self = shift;
+ my $label = shift;
+
+ $label or puke "can't quote an empty label";
+
+ # left and right quote characters
+ my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
+ SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
+ ARRAYREF => sub {@{$self->{quote_char}}},
+ UNDEF => sub {()},
+ });
+ not @other
+ or puke "quote_char must be an arrayref of 2 values";
+
+ # no quoting if no quoting chars
+ $ql or return $label;
+
+ # no quoting for literal SQL
+ return $$label if ref($label) eq 'SCALAR';
+
+ # separate table / column (if applicable)
+ my $sep = $self->{name_sep} || '';
+ my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
+
+ # do the quoting, except for "*" or for `table`.*
+ my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
+
+ # reassemble and return.
+ return join $sep, @quoted;
+}
+
+
+# Conversion, if applicable
+sub _convert ($) {
+ my ($self, $arg) = @_;
+
+# LDNOTE : modified the previous implementation below because
+# it was not consistent : the first "return" is always an array,
+# the second "return" is context-dependent. Anyway, _convert
+# seems always used with just a single argument, so make it a
+# scalar function.
+# return @_ unless $self->{convert};
+# my $conv = $self->_sqlcase($self->{convert});
+# my @ret = map { $conv.'('.$_.')' } @_;
+# return wantarray ? @ret : $ret[0];
+ if ($self->{convert}) {
+ my $conv = $self->_sqlcase($self->{convert});
+ $arg = $conv.'('.$arg.')';
+ }
+ return $arg;
+}
+
+# And bindtype
+sub _bindtype (@) {
+ my $self = shift;
+ my($col, @vals) = @_;
+
+ #LDNOTE : changed original implementation below because it did not make
+ # sense when bindtype eq 'columns' and @vals > 1.
+# return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
+
+ return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
+}
+
+# Dies if any element of @bind is not in [colname => value] format
+# if bindtype is 'columns'.
+sub _assert_bindval_matches_bindtype {
+ my ($self, @bind) = @_;
+
+ if ($self->{bindtype} eq 'columns') {
+ foreach my $val (@bind) {
+ if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
+ die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
+ }
+ }
+ }
+}
+
+sub _join_sql_clauses {
+ my ($self, $logic, $clauses_aref, $bind_aref) = @_;
+
+ if (@$clauses_aref > 1) {
+ my $join = " " . $self->_sqlcase($logic) . " ";
+ my $sql = '( ' . join($join, @$clauses_aref) . ' )';
+ return ($sql, @$bind_aref);
+ }
+ elsif (@$clauses_aref) {
+ return ($clauses_aref->[0], @$bind_aref); # no parentheses
+ }
+ else {
+ return (); # if no SQL, ignore @$bind_aref
+ }
+}
+
+
+# Fix SQL case, if so requested
+sub _sqlcase {
+ my $self = shift;
+
+ # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
+ # don't touch the argument ... crooked logic, but let's not change it!
+ return $self->{case} ? $_[0] : uc($_[0]);
+}
+
+
+#======================================================================
+# DISPATCHING FROM REFKIND
+#======================================================================
+
+sub _refkind {
+ my ($self, $data) = @_;
+ my $suffix = '';
+ my $ref;
+ my $n_steps = 0;
+
+ while (1) {
+ # blessed objects are treated like scalars
+ $ref = (blessed $data) ? '' : ref $data;
+ $n_steps += 1 if $ref;
+ last if $ref ne 'REF';
+ $data = $$data;
+ }
+
+ my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
+
+ return $base . ('REF' x $n_steps);
+}
+
+
+
+sub _try_refkind {
+ my ($self, $data) = @_;
+ my @try = ($self->_refkind($data));
+ push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
+ push @try, 'FALLBACK';
+ return @try;
+}
+
+sub _METHOD_FOR_refkind {
+ my ($self, $meth_prefix, $data) = @_;
+ my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
+ $self->_try_refkind($data)
+ or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
+ return $method;
+}
+
+
+sub _SWITCH_refkind {
+ my ($self, $data, $dispatch_table) = @_;
+
+ my $coderef = first {$_} map {$dispatch_table->{$_}}
+ $self->_try_refkind($data)
+ or puke "no dispatch entry for ".$self->_refkind($data);
+ $coderef->();
+}
+
+
+
+
+#======================================================================
+# VALUES, GENERATE, AUTOLOAD
+#======================================================================
+
+# LDNOTE: original code from nwiger, didn't touch code in that section
+# I feel the AUTOLOAD stuff should not be the default, it should
+# only be activated on explicit demand by user.
+
+sub values {
+ my $self = shift;
+ my $data = shift || return;
+ puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
+ unless ref $data eq 'HASH';
+
+ my @all_bind;
+ foreach my $k ( sort keys %$data ) {
+ my $v = $data->{$k};
+ $self->_SWITCH_refkind($v, {
+ ARRAYREF => sub {
+ if ($self->{array_datatypes}) { # array datatype
+ push @all_bind, $self->_bindtype($k, $v);
+ }
+ else { # literal SQL with bind
+ my ($sql, @bind) = @$v;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @all_bind, @bind;
+ }
+ },
+ ARRAYREFREF => sub { # literal SQL with bind
+ my ($sql, @bind) = @${$v};
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @all_bind, @bind;
+ },
+ SCALARREF => sub { # literal SQL without bind
+ },
+ SCALAR_or_UNDEF => sub {
+ push @all_bind, $self->_bindtype($k, $v);
+ },
+ });
+ }
+
+ return @all_bind;
+}
+
+sub generate {
+ my $self = shift;
+
+ my(@sql, @sqlq, @sqlv);
+
+ for (@_) {
+ my $ref = ref $_;
+ if ($ref eq 'HASH') {
+ for my $k (sort keys %$_) {
+ my $v = $_->{$k};
+ my $r = ref $v;
+ my $label = $self->_quote($k);
+ if ($r eq 'ARRAY') {
+ # literal SQL with bind
+ my ($sql, @bind) = @$v;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @sqlq, "$label = $sql";
+ push @sqlv, @bind;
+ } elsif ($r eq 'SCALAR') {
+ # literal SQL without bind
+ push @sqlq, "$label = $$v";
+ } else {
+ push @sqlq, "$label = ?";
+ push @sqlv, $self->_bindtype($k, $v);
+ }
+ }
+ push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
+ } elsif ($ref eq 'ARRAY') {
+ # unlike insert(), assume these are ONLY the column names, i.e. for SQL
+ for my $v (@$_) {
+ my $r = ref $v;
+ if ($r eq 'ARRAY') { # literal SQL with bind
+ my ($sql, @bind) = @$v;
+ $self->_assert_bindval_matches_bindtype(@bind);
+ push @sqlq, $sql;
+ push @sqlv, @bind;
+ } elsif ($r eq 'SCALAR') { # literal SQL without bind
+ # embedded literal SQL
+ push @sqlq, $$v;
+ } else {
+ push @sqlq, '?';
+ push @sqlv, $v;
+ }
+ }
+ push @sql, '(' . join(', ', @sqlq) . ')';
+ } elsif ($ref eq 'SCALAR') {
+ # literal SQL
+ push @sql, $$_;
+ } else {
+ # strings get case twiddled
+ push @sql, $self->_sqlcase($_);
+ }
+ }
+
+ my $sql = join ' ', @sql;
+
+ # this is pretty tricky
+ # if ask for an array, return ($stmt, @bind)
+ # otherwise, s/?/shift @sqlv/ to put it inline
+ if (wantarray) {
+ return ($sql, @sqlv);
+ } else {
+ 1 while $sql =~ s/\?/my $d = shift(@sqlv);
+ ref $d ? $d->[1] : $d/e;
+ return $sql;
+ }
+}
+
+
+sub DESTROY { 1 }
+
+sub AUTOLOAD {
+ # This allows us to check for a local, then _form, attr
+ my $self = shift;
+ my($name) = $AUTOLOAD =~ /.*::(.+)/;
+ return $self->generate($name, @_);
+}
+
+1;
+
+
+
+__END__
=head1 NAME
$sth->execute(@bind);
# Just generate the WHERE clause
- my($stmt, @bind) = $sql->where(\%where, \@order);
+ my($stmt, @bind) = $sql->where(\%where, \@order);
# Return values in the same order, for hashed queries
# See PERFORMANCE section for more details
my $sth = $dbh->prepare($stmt);
$sth->execute(@bind);
-In addition, you can apply SQL functions to elements of your C<%data>
-by specifying an arrayref for the given hash value. For example, if
-you need to execute the Oracle C<to_date> function on a value, you
-can say something like this:
+=head2 Inserting and Updating Arrays
+
+If your database has array types (like for example Postgres),
+activate the special option C<< array_datatypes => 1 >>
+when creating the C<SQL::Abstract> object.
+Then you may use an arrayref to insert and update database array types:
+
+ my $sql = SQL::Abstract->new(array_datatypes => 1);
+ my %data = (
+ planets => [qw/Mercury Venus Earth Mars/]
+ );
+
+ my($stmt, @bind) = $sql->insert('solar_system', \%data);
+
+This results in:
+
+ $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
+
+ @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
+
+
+=head2 Inserting and Updating SQL
+
+In order to apply SQL functions to elements of your C<%data> you may
+specify a reference to an arrayref for the given hash value. For example,
+if you need to execute the Oracle C<to_date> function on a value, you can
+say something like this:
my %data = (
name => 'Bill',
- date_entered => ["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
+ date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
);
The first value in the array is the actual SQL. Any other values are
want to specify a WHERE clause for your UPDATE, though, which is
where handling C<%where> hashes comes in handy...
+=head2 Complex where statements
+
This module can generate pretty complicated WHERE statements
easily. For example, simple C<key=value> pairs are taken to mean
equality, and if you want to see if a field is within a set
similar order to each function (table, then fields, then a where
clause) to try and simplify things.
-=cut
-
-use Carp;
-use strict;
-
-our $VERSION = '1.22';
-our $REVISION = '$Id$';
-our $AUTOLOAD;
-
-# Fix SQL case, if so requested
-sub _sqlcase {
- my $self = shift;
- return $self->{case} ? $_[0] : uc($_[0]);
-}
-
-# Anon copies of arrays/hashes
-# Based on deep_copy example by merlyn
-# http://www.stonehenge.com/merlyn/UnixReview/col30.html
-sub _anoncopy {
- my $orig = shift;
- return (ref $orig eq 'HASH') ? +{map { $_ => _anoncopy($orig->{$_}) } keys %$orig}
- : (ref $orig eq 'ARRAY') ? [map _anoncopy($_), @$orig]
- : $orig;
-}
-
-# Debug
-sub _debug {
- return unless $_[0]->{debug}; shift; # a little faster
- my $func = (caller(1))[3];
- warn "[$func] ", @_, "\n";
-}
-
-sub belch (@) {
- my($func) = (caller(1))[3];
- carp "[$func] Warning: ", @_;
-}
-
-sub puke (@) {
- my($func) = (caller(1))[3];
- croak "[$func] Fatal: ", @_;
-}
-
-# Utility functions
-sub _table {
- my $self = shift;
- my $tab = shift;
- if (ref $tab eq 'ARRAY') {
- return join ', ', map { $self->_quote($_) } @$tab;
- } else {
- return $self->_quote($tab);
- }
-}
-
-sub _quote {
- my $self = shift;
- my $label = shift;
-
- return $label
- if $label eq '*';
-
- return $self->{quote_char} . $label . $self->{quote_char}
- if !defined $self->{name_sep};
-
- return join $self->{name_sep},
- map { $self->{quote_char} . $_ . $self->{quote_char} }
- split /\Q$self->{name_sep}\E/, $label;
-}
-
-# Conversion, if applicable
-sub _convert ($) {
- my $self = shift;
- return @_ unless $self->{convert};
- my $conv = $self->_sqlcase($self->{convert});
- my @ret = map { $conv.'('.$_.')' } @_;
- return wantarray ? @ret : $ret[0];
-}
-# And bindtype
-sub _bindtype (@) {
- my $self = shift;
- my($col,@val) = @_;
- return $self->{bindtype} eq 'columns' ? [ @_ ] : @val;
-}
-# Modified -logic or -nest
-sub _modlogic ($) {
- my $self = shift;
- my $sym = @_ ? lc(shift) : $self->{logic};
- $sym =~ tr/_/ /;
- $sym = $self->{logic} if $sym eq 'nest';
- return $self->_sqlcase($sym); # override join
-}
=head2 new(option => 'value')
SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
+Any setting other than 'lower' is ignored.
+
=item cmp
This determines what the default comparison operator is. By default
You can also override the comparsion on an individual basis - see
the huge section on L</"WHERE CLAUSES"> at the bottom.
+=item sqltrue, sqlfalse
+
+Expressions for inserting boolean values within SQL statements.
+By default these are C<1=1> and C<1=0>. They are used
+by the special operators C<-in> and C<-not_in> for generating
+correct SQL even when the argument is an empty array (see below).
+
=item logic
This determines the default logical operator for multiple WHERE
-statements in arrays. By default it is "or", meaning that a WHERE
+statements in arrays or hashes. If absent, the default logic is "or"
+for arrays, and "and" for hashes. This means that a WHERE
array of the form:
@where = (
event_date => {'<=', '4/24/03'},
);
-Will generate SQL like this:
+will generate SQL like this:
WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
+The logic can also be changed locally by inserting
+a modifier in front of an arrayref :
+
+ @where = (-and => [event_date => {'>=', '2/13/99'},
+ event_date => {'<=', '4/24/03'} ]);
+
+See the L</"WHERE CLAUSES"> section for explanations.
+
=item convert
This will automatically convert comparisons using the specified SQL
);
You can then iterate through this manually, using DBI's C<bind_param()>.
-
+
$sth->prepare($stmt);
my $i = 1;
for (@bind) {
sub called C<bind_fields()> or something and reuse it repeatedly. You still
get a layer of abstraction over manual SQL specification.
+Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
+construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
+will expect the bind values in this format.
+
=item quote_char
This is the character that a table or column name will be quoted
SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
-This is useful if you have tables or columns that are reserved words
-in your database's SQL dialect.
+Alternatively, you can supply an array ref of two items, the first being the left
+hand quote character, and the second the right hand quote character. For
+example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
+that generates SQL like this:
+
+ SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
+
+Quoting is useful if you have tables or columns names that are reserved
+words in your database's SQL dialect.
=item name_sep
SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
-=back
-
-=cut
+=item array_datatypes
-sub new {
- my $self = shift;
- my $class = ref($self) || $self;
- my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
+When this option is true, arrayrefs in INSERT or UPDATE are
+interpreted as array datatypes and are passed directly
+to the DBI layer.
+When this option is false, arrayrefs are interpreted
+as literal SQL, just like refs to arrayrefs
+(but this behavior is for backwards compatibility; when writing
+new queries, use the "reference to arrayref" syntax
+for literal SQL).
- # choose our case by keeping an option around
- delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
- # override logical operator
- $opt{logic} = uc $opt{logic} if $opt{logic};
+=item special_ops
- # how to return bind vars
- $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
+Takes a reference to a list of "special operators"
+to extend the syntax understood by L<SQL::Abstract>.
+See section L</"SPECIAL OPERATORS"> for details.
- # default comparison is "=", but can be overridden
- $opt{cmp} ||= '=';
- # default quotation character around tables/columns
- $opt{quote_char} ||= '';
- return bless \%opt, $class;
-}
+=back
=head2 insert($table, \@values || \%fieldvals)
This is the simplest function. You simply give it a table name
and either an arrayref of values or hashref of field/value pairs.
It returns an SQL INSERT statement and a list of bind values.
-
-=cut
-
-sub insert {
- my $self = shift;
- my $table = $self->_table(shift);
- my $data = shift || return;
-
- my $sql = $self->_sqlcase('insert into') . " $table ";
- my(@sqlf, @sqlv, @sqlq) = ();
-
- my $ref = ref $data;
- if ($ref eq 'HASH') {
- for my $k (sort keys %$data) {
- my $v = $data->{$k};
- my $r = ref $v;
- # named fields, so must save names in order
- push @sqlf, $self->_quote($k);
- if ($r eq 'ARRAY') {
- # SQL included for values
- my @val = @$v;
- push @sqlq, shift @val;
- push @sqlv, $self->_bindtype($k, @val);
- } elsif ($r eq 'SCALAR') {
- # embedded literal SQL
- push @sqlq, $$v;
- } else {
- push @sqlq, '?';
- push @sqlv, $self->_bindtype($k, $v);
- }
- }
- $sql .= '(' . join(', ', @sqlf) .') '. $self->_sqlcase('values') . ' ('. join(', ', @sqlq) .')';
- } elsif ($ref eq 'ARRAY') {
- # just generate values(?,?) part
- # no names (arrayref) so can't generate bindtype
- carp "Warning: ",__PACKAGE__,"->insert called with arrayref when bindtype set"
- if $self->{bindtype} ne 'normal';
- for my $v (@$data) {
- my $r = ref $v;
- if ($r eq 'ARRAY') {
- my @val = @$v;
- push @sqlq, shift @val;
- push @sqlv, @val;
- } elsif ($r eq 'SCALAR') {
- # embedded literal SQL
- push @sqlq, $$v;
- } else {
- push @sqlq, '?';
- push @sqlv, $v;
- }
- }
- $sql .= $self->_sqlcase('values') . ' ('. join(', ', @sqlq) .')';
- } elsif ($ref eq 'SCALAR') {
- # literal SQL
- $sql .= $$data;
- } else {
- puke "Unsupported data type specified to \$sql->insert";
- }
-
- return wantarray ? ($sql, @sqlv) : $sql;
-}
+See the sections on L</"Inserting and Updating Arrays"> and
+L</"Inserting and Updating SQL"> for information on how to insert
+with those data types.
=head2 update($table, \%fieldvals, \%where)
This takes a table, hashref of field/value pairs, and an optional
-hashref WHERE clause. It returns an SQL UPDATE function and a list
+hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
of bind values.
+See the sections on L</"Inserting and Updating Arrays"> and
+L</"Inserting and Updating SQL"> for information on how to insert
+with those data types.
-=cut
-
-sub update {
- my $self = shift;
- my $table = $self->_table(shift);
- my $data = shift || return;
- my $where = shift;
-
- my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ');
- my(@sqlf, @sqlv) = ();
-
- puke "Unsupported data type specified to \$sql->update"
- unless ref $data eq 'HASH';
-
- for my $k (sort keys %$data) {
- my $v = $data->{$k};
- my $r = ref $v;
- my $label = $self->_quote($k);
- if ($r eq 'ARRAY') {
- # SQL included for values
- my @bind = @$v;
- my $sql = shift @bind;
- push @sqlf, "$label = $sql";
- push @sqlv, $self->_bindtype($k, @bind);
- } elsif ($r eq 'SCALAR') {
- # embedded literal SQL
- push @sqlf, "$label = $$v";
- } else {
- push @sqlf, "$label = ?";
- push @sqlv, $self->_bindtype($k, $v);
- }
- }
-
- $sql .= join ', ', @sqlf;
-
- if ($where) {
- my($wsql, @wval) = $self->where($where);
- $sql .= $wsql;
- push @sqlv, @wval;
- }
-
- return wantarray ? ($sql, @sqlv) : $sql;
-}
-
-=head2 select($table, \@fields, \%where, \@order)
-
-This takes a table, arrayref of fields (or '*'), optional hashref
-WHERE clause, and optional arrayref order by, and returns the
-corresponding SQL SELECT statement and list of bind values.
-
-=cut
-
-sub select {
- my $self = shift;
- my $table = $self->_table(shift);
- my $fields = shift || '*';
- my $where = shift;
- my $order = shift;
-
- my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields : $fields;
- my $sql = join ' ', $self->_sqlcase('select'), $f, $self->_sqlcase('from'), $table;
-
- my(@sqlf, @sqlv) = ();
- my($wsql, @wval) = $self->where($where, $order);
- $sql .= $wsql;
- push @sqlv, @wval;
-
- return wantarray ? ($sql, @sqlv) : $sql;
-}
-
-=head2 delete($table, \%where)
-
-This takes a table name and optional hashref WHERE clause.
-It returns an SQL DELETE statement and list of bind values.
-
-=cut
-
-sub delete {
- my $self = shift;
- my $table = $self->_table(shift);
- my $where = shift;
+=head2 select($source, $fields, $where, $order)
- my $sql = $self->_sqlcase('delete from') . " $table";
- my(@sqlf, @sqlv) = ();
+This returns a SQL SELECT statement and associated list of bind values, as
+specified by the arguments :
- if ($where) {
- my($wsql, @wval) = $self->where($where);
- $sql .= $wsql;
- push @sqlv, @wval;
- }
+=over
- return wantarray ? ($sql, @sqlv) : $sql;
-}
+=item $source
-=head2 where(\%where, \@order)
+Specification of the 'FROM' part of the statement.
+The argument can be either a plain scalar (interpreted as a table
+name, will be quoted), or an arrayref (interpreted as a list
+of table names, joined by commas, quoted), or a scalarref
+(literal table name, not quoted), or a ref to an arrayref
+(list of literal table names, joined by commas, not quoted).
-This is used to generate just the WHERE clause. For example,
-if you have an arbitrary data structure and know what the
-rest of your SQL is going to look like, but want an easy way
-to produce a WHERE clause, use this. It returns an SQL WHERE
-clause and list of bind values.
+=item $fields
-=cut
+Specification of the list of fields to retrieve from
+the source.
+The argument can be either an arrayref (interpreted as a list
+of field names, will be joined by commas and quoted), or a
+plain scalar (literal SQL, not quoted).
+Please observe that this API is not as flexible as for
+the first argument C<$table>, for backwards compatibility reasons.
-# Finally, a separate routine just to handle WHERE clauses
-sub where {
- my $self = shift;
- my $where = shift;
- my $order = shift;
-
- # Need a separate routine to properly wrap w/ "where"
- my $sql = '';
- my @ret = $self->_recurse_where($where);
- if (@ret) {
- my $wh = shift @ret;
- $sql .= $self->_sqlcase(' where ') . $wh if $wh;
- }
+=item $where
- # order by?
- if ($order) {
- $sql .= $self->_order_by($order);
- }
+Optional argument to specify the WHERE part of the query.
+The argument is most often a hashref, but can also be
+an arrayref or plain scalar --
+see section L<WHERE clause|/"WHERE CLAUSES"> for details.
- return wantarray ? ($sql, @ret) : $sql;
-}
+=item $order
+Optional argument to specify the ORDER BY part of the query.
+The argument can be a scalar, a hashref or an arrayref
+-- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
+for details.
-sub _recurse_where {
- local $^W = 0; # really, you've gotta be fucking kidding me
- my $self = shift;
- my $where = _anoncopy(shift); # prevent destroying original
- my $ref = ref $where || '';
- my $join = shift || $self->{logic} ||
- ($ref eq 'ARRAY' ? $self->_sqlcase('or') : $self->_sqlcase('and'));
-
- # For assembling SQL fields and values
- my(@sqlf, @sqlv) = ();
-
- # If an arrayref, then we join each element
- if ($ref eq 'ARRAY') {
- # need to use while() so can shift() for arrays
- my $subjoin;
- while (my $el = shift @$where) {
-
- # skip empty elements, otherwise get invalid trailing AND stuff
- if (my $ref2 = ref $el) {
- if ($ref2 eq 'ARRAY') {
- next unless @$el;
- } elsif ($ref2 eq 'HASH') {
- next unless %$el;
- $subjoin ||= $self->_sqlcase('and');
- } elsif ($ref2 eq 'SCALAR') {
- # literal SQL
- push @sqlf, $$el;
- next;
- }
- $self->_debug("$ref2(*top) means join with $subjoin");
- } else {
- # top-level arrayref with scalars, recurse in pairs
- $self->_debug("NOREF(*top) means join with $subjoin");
- $el = {$el => shift(@$where)};
- }
- my @ret = $self->_recurse_where($el, $subjoin);
- push @sqlf, shift @ret;
- push @sqlv, @ret;
- }
- }
- elsif ($ref eq 'HASH') {
- # Note: during recursion, the last element will always be a hashref,
- # since it needs to point a column => value. So this be the end.
- for my $k (sort keys %$where) {
- my $v = $where->{$k};
- my $label = $self->_quote($k);
- if ($k =~ /^-(\D+)/) {
- # special nesting, like -and, -or, -nest, so shift over
- my $subjoin = $self->_modlogic($1);
- $self->_debug("OP(-$1) means special logic ($subjoin), recursing...");
- my @ret = $self->_recurse_where($v, $subjoin);
- push @sqlf, shift @ret;
- push @sqlv, @ret;
- } elsif (! defined($v)) {
- # undef = null
- $self->_debug("UNDEF($k) means IS NULL");
- push @sqlf, $label . $self->_sqlcase(' is null');
- } elsif (ref $v eq 'ARRAY') {
- my @v = @$v;
-
- # multiple elements: multiple options
- $self->_debug("ARRAY($k) means multiple elements: [ @v ]");
-
- # special nesting, like -and, -or, -nest, so shift over
- my $subjoin = $self->_sqlcase('or');
- if ($v[0] =~ /^-(\D+)/) {
- $subjoin = $self->_modlogic($1); # override subjoin
- $self->_debug("OP(-$1) means special logic ($subjoin), shifting...");
- shift @v;
- }
+=back
- # map into an array of hashrefs and recurse
- my @ret = $self->_recurse_where([map { {$k => $_} } @v], $subjoin);
-
- # push results into our structure
- push @sqlf, shift @ret;
- push @sqlv, @ret;
- } elsif (ref $v eq 'HASH') {
- # modified operator { '!=', 'completed' }
- for my $f (sort keys %$v) {
- my $x = $v->{$f};
- $self->_debug("HASH($k) means modified operator: { $f }");
-
- # check for the operator being "IN" or "BETWEEN" or whatever
- if (ref $x eq 'ARRAY') {
- if ($f =~ /^-?\s*(not[\s_]+)?(in|between)\s*$/i) {
- my $u = $self->_modlogic($1 . $2);
- $self->_debug("HASH($f => $x) uses special operator: [ $u ]");
- if ($u =~ /between/i) {
- # SQL sucks
- push @sqlf, join ' ', $self->_convert($label), $u, $self->_convert('?'),
- $self->_sqlcase('and'), $self->_convert('?');
- } else {
- push @sqlf, join ' ', $self->_convert($label), $u, '(',
- join(', ', map { $self->_convert('?') } @$x),
- ')';
- }
- push @sqlv, $self->_bindtype($k, @$x);
- } else {
- # multiple elements: multiple options
- $self->_debug("ARRAY($x) means multiple elements: [ @$x ]");
-
- # map into an array of hashrefs and recurse
- my @ret = $self->_recurse_where([map { {$k => {$f, $_}} } @$x]);
-
- # push results into our structure
- push @sqlf, shift @ret;
- push @sqlv, @ret;
- }
- } elsif (! defined($x)) {
- # undef = NOT null
- my $not = ($f eq '!=' || $f eq 'not like') ? ' not' : '';
- push @sqlf, $label . $self->_sqlcase(" is$not null");
- } else {
- # regular ol' value
- $f =~ s/^-//; # strip leading -like =>
- $f =~ s/_/ /; # _ => " "
- push @sqlf, join ' ', $self->_convert($label), $self->_sqlcase($f), $self->_convert('?');
- push @sqlv, $self->_bindtype($k, $x);
- }
- }
- } elsif (ref $v eq 'SCALAR') {
- # literal SQL
- $self->_debug("SCALAR($k) means literal SQL: $$v");
- push @sqlf, "$label $$v";
- } else {
- # standard key => val
- $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
- push @sqlf, join ' ', $self->_convert($label), $self->_sqlcase($self->{cmp}), $self->_convert('?');
- push @sqlv, $self->_bindtype($k, $v);
- }
- }
- }
- elsif ($ref eq 'SCALAR') {
- # literal sql
- $self->_debug("SCALAR(*top) means literal SQL: $$where");
- push @sqlf, $$where;
- }
- elsif (defined $where) {
- # literal sql
- $self->_debug("NOREF(*top) means literal SQL: $where");
- push @sqlf, $where;
- }
- # assemble and return sql
- my $wsql = @sqlf ? '( ' . join(" $join ", @sqlf) . ' )' : '';
- return wantarray ? ($wsql, @sqlv) : $wsql;
-}
+=head2 delete($table, \%where)
-sub _order_by {
- my $self = shift;
- my $ref = ref $_[0];
+This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
+It returns an SQL DELETE statement and list of bind values.
- my @vals = $ref eq 'ARRAY' ? @{$_[0]} :
- $ref eq 'SCALAR' ? ${$_[0]} :
- $ref eq '' ? $_[0] :
- puke "Unsupported data struct $ref for ORDER BY";
+=head2 where(\%where, \@order)
+
+This is used to generate just the WHERE clause. For example,
+if you have an arbitrary data structure and know what the
+rest of your SQL is going to look like, but want an easy way
+to produce a WHERE clause, use this. It returns an SQL WHERE
+clause and list of bind values.
- my $val = join ', ', map { $self->_quote($_) } @vals;
- return $val ? $self->_sqlcase(' order by')." $val" : '';
-}
=head2 values(\%data)
Using this allows you to markedly speed up your queries if you
are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
-=cut
-
-sub values {
- my $self = shift;
- my $data = shift || return;
- puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
- unless ref $data eq 'HASH';
- return map { $self->_bindtype($_, $data->{$_}) } sort keys %$data;
-}
-
=head2 generate($any, 'number', $of, \@data, $struct, \%types)
Warning: This is an experimental method and subject to change.
You get the idea. Strings get their case twiddled, but everything
else remains verbatim.
-=cut
-
-sub generate {
- my $self = shift;
-
- my(@sql, @sqlq, @sqlv);
-
- for (@_) {
- my $ref = ref $_;
- if ($ref eq 'HASH') {
- for my $k (sort keys %$_) {
- my $v = $_->{$k};
- my $r = ref $v;
- my $label = $self->_quote($k);
- if ($r eq 'ARRAY') {
- # SQL included for values
- my @bind = @$v;
- my $sql = shift @bind;
- push @sqlq, "$label = $sql";
- push @sqlv, $self->_bindtype($k, @bind);
- } elsif ($r eq 'SCALAR') {
- # embedded literal SQL
- push @sqlq, "$label = $$v";
- } else {
- push @sqlq, "$label = ?";
- push @sqlv, $self->_bindtype($k, $v);
- }
- }
- push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
- } elsif ($ref eq 'ARRAY') {
- # unlike insert(), assume these are ONLY the column names, i.e. for SQL
- for my $v (@$_) {
- my $r = ref $v;
- if ($r eq 'ARRAY') {
- my @val = @$v;
- push @sqlq, shift @val;
- push @sqlv, @val;
- } elsif ($r eq 'SCALAR') {
- # embedded literal SQL
- push @sqlq, $$v;
- } else {
- push @sqlq, '?';
- push @sqlv, $v;
- }
- }
- push @sql, '(' . join(', ', @sqlq) . ')';
- } elsif ($ref eq 'SCALAR') {
- # literal SQL
- push @sql, $$_;
- } else {
- # strings get case twiddled
- push @sql, $self->_sqlcase($_);
- }
- }
-
- my $sql = join ' ', @sql;
-
- # this is pretty tricky
- # if ask for an array, return ($stmt, @bind)
- # otherwise, s/?/shift @sqlv/ to put it inline
- if (wantarray) {
- return ($sql, @sqlv);
- } else {
- 1 while $sql =~ s/\?/my $d = shift(@sqlv);
- ref $d ? $d->[1] : $d/e;
- return $sql;
- }
-}
-
-sub DESTROY { 1 }
-sub AUTOLOAD {
- # This allows us to check for a local, then _form, attr
- my $self = shift;
- my($name) = $AUTOLOAD =~ /.*::(.+)/;
- return $self->generate($name, @_);
-}
-1;
-__END__
=head1 WHERE CLAUSES
+=head2 Introduction
+
This module uses a variation on the idea from L<DBIx::Abstract>. It
is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
module is that things in arrays are OR'ed, and things in hashes
However, note that the C<%where> hash can be used directly in any
of the other functions as well, as described above.
+=head2 Key-value pairs
+
So, let's get started. To begin, a simple hash:
my %where = (
$stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
@bind = ('nwiger', 'assigned', 'in-progress', 'pending');
+A field associated to an empty arrayref will be considered a
+logical false and will generate 0=1.
+
+=head2 Specific comparison operators
+
If you want to specify a different type of operator for your comparison,
you can use a hashref for a given column:
To test against multiple values, just enclose the values in an arrayref:
- status => { '!=', ['assigned', 'in-progress', 'pending'] };
+ status => { '=', ['assigned', 'in-progress', 'pending'] };
Which would give you:
- "WHERE status != ? OR status != ? OR status != ?"
+ "WHERE status = ? OR status = ? OR status = ?"
+
-But, this is probably not what you want in this case (look at it). So
-the hashref can also contain multiple pairs, in which case it is expanded
+The hashref can also contain multiple pairs, in which case it is expanded
into an C<AND> of its elements:
my %where = (
$stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
@bind = ('nwiger', 'completed', 'pending%');
+
To get an OR instead, you can combine it with the arrayref idea:
my %where => (
$stmt = "WHERE user = ? AND priority = ? OR priority != ?";
@bind = ('nwiger', '2', '1');
-However, there is a subtle trap if you want to say something like
+If you want to include literal SQL (with or without bind values), just use a
+scalar reference or array reference as the value:
+
+ my %where = (
+ date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
+ date_expires => { '<' => \"now()" }
+ );
+
+Which would generate:
+
+ $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
+ @bind = ('11/26/2008');
+
+
+=head2 Logic and nesting operators
+
+In the example above,
+there is a subtle trap if you want to say something like
this (notice the C<AND>):
WHERE priority != ? AND priority != ?
As the second C<!=> key will obliterate the first. The solution
is to use the special C<-modifier> form inside an arrayref:
- priority => [ -and => {'!=', 2}, {'!=', 1} ]
+ priority => [ -and => {'!=', 2},
+ {'!=', 1} ]
+
Normally, these would be joined by C<OR>, but the modifier tells it
to use C<AND> instead. (Hint: You can use this in conjunction with the
status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
-In addition to C<-and> and C<-or>, there is also a special C<-nest>
-operator which adds an additional set of parens, to create a subquery.
-For example, to get something like this:
-
- $stmt = WHERE user = ? AND ( workhrs > ? OR geo = ? )
- @bind = ('nwiger', '20', 'ASIA');
-You would do:
- my %where = (
- user => 'nwiger',
- -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
- );
+=head2 Special operators : IN, BETWEEN, etc.
You can also use the hashref format to compare a list of fields using the
C<IN> comparison operator, by specifying the list as an arrayref:
$stmt = "WHERE status = ? AND reportid IN (?,?,?)";
@bind = ('completed', '567', '2335', '2');
-You can use this same format to use other grouping functions, such
-as C<BETWEEN>, C<SOME>, and so forth. For example:
+The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
+the same way.
+
+If the argument to C<-in> is an empty array, 'sqlfalse' is generated
+(by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
+'sqltrue' (by default : C<1=1>).
+
+
+
+Another pair of operators is C<-between> and C<-not_between>,
+used with an arrayref of two values:
my %where = (
user => 'nwiger',
WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
+These are the two builtin "special operators"; but the
+list can be expanded : see section L</"SPECIAL OPERATORS"> below.
+
+=head2 Nested conditions, -and/-or prefixes
+
So far, we've seen how multiple conditions are joined with a top-level
C<AND>. We can change this by putting the different conditions we want in
hashes and then putting those hashes in an array. For example:
OR ( user = ? AND status = ? ) )";
@bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
-This can be combined with the C<-nest> operator to properly group
-SQL statements:
+
+There is also a special C<-nest>
+operator which adds an additional set of parens, to create a subquery.
+For example, to get something like this:
+
+ $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
+ @bind = ('nwiger', '20', 'ASIA');
+
+You would do:
+
+ my %where = (
+ user => 'nwiger',
+ -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
+ );
+
+
+Finally, clauses in hashrefs or arrayrefs can be
+prefixed with an C<-and> or C<-or> to change the logic
+inside :
my @where = (
-and => [
( ( workhrs > ? AND geo = ? )
OR ( workhrs < ? AND geo = ? ) ) )
+
+=head2 Algebraic inconsistency, for historical reasons
+
+C<Important note>: when connecting several conditions, the C<-and->|C<-or>
+operator goes C<outside> of the nested structure; whereas when connecting
+several constraints on one column, the C<-and> operator goes
+C<inside> the arrayref. Here is an example combining both features :
+
+ my @where = (
+ -and => [a => 1, b => 2],
+ -or => [c => 3, d => 4],
+ e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
+ )
+
+yielding
+
+ WHERE ( ( ( a = ? AND b = ? )
+ OR ( c = ? OR d = ? )
+ OR ( e LIKE ? AND e LIKE ? ) ) )
+
+This difference in syntax is unfortunate but must be preserved for
+historical reasons. So be careful : the two examples below would
+seem algebraically equivalent, but they are not
+
+ {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
+ # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
+
+ [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
+ # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
+
+
+=head2 Literal SQL
+
Finally, sometimes only literal SQL will do. If you want to include
literal SQL verbatim, you can specify it as a scalar reference, namely:
requestor => { '!=', undef },
);
+
TMTOWTDI.
+Conditions on boolean columns can be expressed in the
+same way, passing a reference to an empty string :
+
+ my %where = (
+ priority => { '<', 2 },
+ is_ready => \"";
+ );
+
+which yields
+
+ $stmt = "WHERE priority < ? AND is_ready";
+ @bind = ('2');
+
+
+=head2 Literal SQL with placeholders and bind values (subqueries)
+
+If the literal SQL to be inserted has placeholders and bind values,
+use a reference to an arrayref (yes this is a double reference --
+not so common, but perfectly legal Perl). For example, to find a date
+in Postgres you can use something like this:
+
+ my %where = (
+ date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
+ )
+
+This would create:
+
+ $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
+ @bind = ('10');
+
+Note that you must pass the bind values in the same format as they are returned
+by L</where>. That means that if you set L</bindtype> to C<columns>, you must
+provide the bind values in the C<< [ column_meta => value ] >> format, where
+C<column_meta> is an opaque scalar value; most commonly the column name, but
+you can use any scalar value (including references and blessed references),
+L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
+to C<columns> the above example will look like:
+
+ my %where = (
+ date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
+ )
+
+Literal SQL is especially useful for nesting parenthesized clauses in the
+main SQL query. Here is a first example :
+
+ my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
+ 100, "foo%");
+ my %where = (
+ foo => 1234,
+ bar => \["IN ($sub_stmt)" => @sub_bind],
+ );
+
+This yields :
+
+ $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
+ WHERE c2 < ? AND c3 LIKE ?))";
+ @bind = (1234, 100, "foo%");
+
+Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
+are expressed in the same way. Of course the C<$sub_stmt> and
+its associated bind values can be generated through a former call
+to C<select()> :
+
+ my ($sub_stmt, @sub_bind)
+ = $sql->select("t1", "c1", {c2 => {"<" => 100},
+ c3 => {-like => "foo%"}});
+ my %where = (
+ foo => 1234,
+ bar => \["> ALL ($sub_stmt)" => @sub_bind],
+ );
+
+In the examples above, the subquery was used as an operator on a column;
+but the same principle also applies for a clause within the main C<%where>
+hash, like an EXISTS subquery :
+
+ my ($sub_stmt, @sub_bind)
+ = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
+ my %where = (
+ foo => 1234,
+ -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
+ );
+
+which yields
+
+ $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
+ WHERE c1 = ? AND c2 > t0.c0))";
+ @bind = (1234, 1);
+
+
+Observe that the condition on C<c2> in the subquery refers to
+column C<t0.c0> of the main query : this is I<not> a bind
+value, so we have to express it through a scalar ref.
+Writing C<< c2 => {">" => "t0.c0"} >> would have generated
+C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
+what we wanted here.
+
+Another use of the subquery technique is when some SQL clauses need
+parentheses, as it often occurs with some proprietary SQL extensions
+like for example fulltext expressions, geospatial expressions,
+NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
+
+ my %where = (
+ -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
+ );
+
+Finally, here is an example where a subquery is used
+for expressing unary negation:
+
+ my ($sub_stmt, @sub_bind)
+ = $sql->where({age => [{"<" => 10}, {">" => 20}]});
+ $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
+ my %where = (
+ lname => {like => '%son%'},
+ -nest => \["NOT ($sub_stmt)" => @sub_bind],
+ );
+
+This yields
+
+ $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
+ @bind = ('%son%', 10, 20)
+
+
+
+=head2 Conclusion
+
These pages could go on for a while, since the nesting of the data
structures this module can handle are pretty much unlimited (the
module implements the C<WHERE> expansion as a recursive function
dynamically-generating SQL and could just hardwire it into your
script.
+
+
+
+=head1 ORDER BY CLAUSES
+
+Some functions take an order by clause. This can either be a scalar (just a
+column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
+or an array of either of the two previous forms. Examples:
+
+ Given | Will Generate
+ ----------------------------------------------------------
+ |
+ \'colA DESC' | ORDER BY colA DESC
+ |
+ 'colA' | ORDER BY colA
+ |
+ [qw/colA colB/] | ORDER BY colA, colB
+ |
+ {-asc => 'colA'} | ORDER BY colA ASC
+ |
+ {-desc => 'colB'} | ORDER BY colB DESC
+ |
+ ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
+ |
+ { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC
+ |
+ [ |
+ { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
+ { -desc => [qw/colB/], | colC ASC, colD ASC
+ { -asc => [qw/colC colD/],|
+ ] |
+ ===========================================================
+
+
+
+=head1 SPECIAL OPERATORS
+
+ my $sqlmaker = SQL::Abstract->new(special_ops => [
+ {regex => qr/.../,
+ handler => sub {
+ my ($self, $field, $op, $arg) = @_;
+ ...
+ },
+ },
+ ]);
+
+A "special operator" is a SQL syntactic clause that can be
+applied to a field, instead of a usual binary operator.
+For example :
+
+ WHERE field IN (?, ?, ?)
+ WHERE field BETWEEN ? AND ?
+ WHERE MATCH(field) AGAINST (?, ?)
+
+Special operators IN and BETWEEN are fairly standard and therefore
+are builtin within C<SQL::Abstract>. For other operators,
+like the MATCH .. AGAINST example above which is
+specific to MySQL, you can write your own operator handlers :
+supply a C<special_ops> argument to the C<new> method.
+That argument takes an arrayref of operator definitions;
+each operator definition is a hashref with two entries
+
+=over
+
+=item regex
+
+the regular expression to match the operator
+
+=item handler
+
+coderef that will be called when meeting that operator
+in the input tree. The coderef will be called with
+arguments C<< ($self, $field, $op, $arg) >>, and
+should return a C<< ($sql, @bind) >> structure.
+
+=back
+
+For example, here is an implementation
+of the MATCH .. AGAINST syntax for MySQL
+
+ my $sqlmaker = SQL::Abstract->new(special_ops => [
+
+ # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
+ {regex => qr/^match$/i,
+ handler => sub {
+ my ($self, $field, $op, $arg) = @_;
+ $arg = [$arg] if not ref $arg;
+ my $label = $self->_quote($field);
+ my ($placeholder) = $self->_convert('?');
+ my $placeholders = join ", ", (($placeholder) x @$arg);
+ my $sql = $self->_sqlcase('match') . " ($label) "
+ . $self->_sqlcase('against') . " ($placeholders) ";
+ my @bind = $self->_bindtype($field, @$arg);
+ return ($sql, @bind);
+ }
+ },
+
+ ]);
+
+
=head1 PERFORMANCE
Thanks to some benchmarking by Mark Stosberg, it turns out that
around. On subsequent queries, simply use the C<values> function provided
by this module to return your values in the correct order.
+
=head1 FORMBUILDER
If you use my C<CGI::FormBuilder> module at all, you'll hopefully
use these three modules together to write complex database query
apps in under 50 lines.
-=head1 NOTES
-There is not (yet) any explicit support for SQL compound logic
-statements like "AND NOT". Instead, just do the de Morgan's
-law transformations yourself. For example, this:
+=head1 CHANGES
- "lname LIKE '%son%' AND NOT ( age < 10 OR age > 20 )"
+Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
+Great care has been taken to preserve the I<published> behavior
+documented in previous versions in the 1.* family; however,
+some features that were previously undocumented, or behaved
+differently from the documentation, had to be changed in order
+to clarify the semantics. Hence, client code that was relying
+on some dark areas of C<SQL::Abstract> v1.*
+B<might behave differently> in v1.50.
-Becomes:
+The main changes are :
- "lname LIKE '%son%' AND ( age >= 10 AND age <= 20 )"
+=over
-With the corresponding C<%where> hash:
+=item *
+
+support for literal SQL through the C<< \ [$sql, bind] >> syntax.
+
+=item *
+
+support for the { operator => \"..." } construct (to embed literal SQL)
+
+=item *
+
+support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
+
+=item *
+
+optional support for L<array datatypes|/"Inserting and Updating Arrays">
+
+=item *
+
+defensive programming : check arguments
+
+=item *
+
+fixed bug with global logic, which was previously implemented
+through global variables yielding side-effects. Prior versions would
+interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
+as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
+Now this is interpreted
+as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
+
+
+=item *
+
+fixed semantics of _bindtype on array args
+
+=item *
+
+dropped the C<_anoncopy> of the %where tree. No longer necessary,
+we just avoid shifting arrays within that tree.
+
+=item *
+
+dropped the C<_modlogic> function
+
+=back
- %where = (
- lname => {like => '%son%'},
- age => [-and => {'>=', 10}, {'<=', 20}],
- );
-Again, remember that the C<-and> goes I<inside> the arrayref.
=head1 ACKNOWLEDGEMENTS
this module. Unfortunately, most of them submitted bugs via CPAN
so I have no idea who they are! But the people I do know are:
+ Ash Berlin (order_by hash term support)
+ Matt Trout (DBIx::Class support)
Mark Stosberg (benchmarking)
Chas Owens (initial "IN" operator support)
Philip Collins (per-field SQL functions)
Eric Kolve (hashref "AND" support)
Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
Dan Kubb (support for "quote_char" and "name_sep")
+ Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
+ Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
+ Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
+ Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
Thanks!
-=head1 BUGS
-
-If found, please DO NOT submit anything via C<rt.cpan.org> - that
-just causes me a ton of work. Email me a patch (or script demonstrating
-the problem) to the below address, and include the VERSION string you'll
-be seeing shortly.
-
=head1 SEE ALSO
-L<DBIx::Abstract>, L<DBI|DBI>, L<CGI::FormBuilder>, L<HTML::QuickTable>
+L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
-=head1 VERSION
+=head1 AUTHOR
-1.22
+Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
-=head1 AUTHOR
+This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
-Copyright (c) 2001-2006 Nathan Wiger <nate@wiger.org>. All Rights Reserved.
+For support, your best bet is to try the C<DBIx::Class> users mailing list.
+While not an official support venue, C<DBIx::Class> makes heavy use of
+C<SQL::Abstract>, and as such list members there are very familiar with
+how to create queries.
This module is free software; you may copy this under the terms of
the GNU General Public License, or the Artistic License, copies of
projects / scpubgit/Q-Branch.git / blobdiff