X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FAbstract.pm;h=ed4bb33ca2299b4d69cbae8c12bca09eeb7267c9;hb=bbde1e88e7a995cd59c7d2e568555c6c716860c6;hp=fcee0f9fbc7061b6385eb47021f90fd235d0ab70;hpb=8a0d798a7a265eec82275bb0b67e620bb85d27ab;p=scpubgit%2FQ-Branch.git diff --git a/lib/SQL/Abstract.pm b/lib/SQL/Abstract.pm index fcee0f9..ed4bb33 100644 --- a/lib/SQL/Abstract.pm +++ b/lib/SQL/Abstract.pm @@ -15,17 +15,18 @@ use Scalar::Util qw/blessed/; # GLOBALS #====================================================================== -our $VERSION = '1.49_01'; -$VERSION = eval $VERSION; # numify for warning-free dev releases +our $VERSION = '1.54'; +# This would confuse some packagers +#$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$/i, handler => \&_where_field_IN}, + {regex => qr/^(not )?between$/i, handler => '_where_field_BETWEEN'}, + {regex => qr/^(not )?in$/i, handler => '_where_field_IN'}, ); #====================================================================== @@ -62,7 +63,7 @@ sub new { delete $opt{case} if $opt{case} && $opt{case} ne 'lower'; # default logic for interpreting arrayrefs - $opt{logic} = uc $opt{logic} || 'OR'; + $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR'; # how to return bind vars # LDNOTE: changed nwiger code : why this 'delete' ?? @@ -110,18 +111,7 @@ sub _insert_HASHREF { # explicit list of fields and then values my @fields = sort keys %$data; - my ($sql, @bind); - { # get values (need temporary override of bindtype to avoid an error) - local $self->{bindtype} = 'normal'; - ($sql, @bind) = $self->_insert_ARRAYREF([@{$data}{@fields}]); - } - - # if necessary, transform values according to 'bindtype' - if ($self->{bindtype} eq 'columns') { - for my $i (0 .. $#fields) { - ($bind[$i]) = $self->_bindtype($fields[$i], $bind[$i]); - } - } + my ($sql, @bind) = $self->_insert_values($data); # assemble SQL $_ = $self->_quote($_) foreach @fields; @@ -137,18 +127,48 @@ sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) $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 ($$data); +} + +sub _insert_values { + my ($self, $data) = @_; + my (@values, @all_bind); - for my $v (@$data) { + foreach my $column (sort keys %$data) { + my $v = $data->{$column}; $self->_SWITCH_refkind($v, { ARRAYREF => sub { if ($self->{array_datatypes}) { # if array datatype are activated push @values, '?'; - push @all_bind, $v; + push @all_bind, $self->_bindtype($column, $v); } else { # else literal SQL with bind my ($sql, @bind) = @$v; + $self->_assert_bindval_matches_bindtype(@bind); push @values, $sql; push @all_bind, @bind; } @@ -156,6 +176,7 @@ sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) ARRAYREFREF => sub { # literal SQL with bind my ($sql, @bind) = @${$v}; + $self->_assert_bindval_matches_bindtype(@bind); push @values, $sql; push @all_bind, @bind; }, @@ -165,7 +186,7 @@ sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) #TODO in SQLA >= 2.0 it will die instead belch "HASH ref as bind value in insert is not supported"; push @values, '?'; - push @all_bind, $v; + push @all_bind, $self->_bindtype($column, $v); }, SCALARREF => sub { # literal SQL without bind @@ -174,7 +195,7 @@ sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) SCALAR_or_UNDEF => sub { push @values, '?'; - push @all_bind, $v; + push @all_bind, $self->_bindtype($column, $v); }, }); @@ -186,19 +207,6 @@ sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) } -sub _insert_ARRAYREFREF { # literal SQL with bind - my ($self, $data) = @_; - return @${$data}; -} - - -sub _insert_SCALARREF { # literal SQL without bind - my ($self, $data) = @_; - - return ($$data); -} - - #====================================================================== # UPDATE methods @@ -229,14 +237,16 @@ sub update { } else { # literal SQL with bind my ($sql, @bind) = @$v; + $self->_assert_bindval_matches_bindtype(@bind); push @set, "$label = $sql"; - push @all_bind, $self->_bindtype($k, @bind); + 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, $self->_bindtype($k, @bind); + push @all_bind, @bind; }, SCALARREF => sub { # literal SQL without bind push @set, "$label = $$v"; @@ -357,17 +367,7 @@ sub _where_ARRAYREF { my @clauses = @$where; - # if the array starts with [-and|or => ...], recurse with that logic - my $first = $clauses[0] || ''; - if ($first =~ /^-(and|or)/i) { - $logic = $1; - shift @clauses; - return $self->_where_ARRAYREF(\@clauses, $logic); - } - - #otherwise.. my (@sql_clauses, @all_bind); - # need to use while() so can shift() for pairs while (my $el = shift @clauses) { @@ -377,6 +377,8 @@ sub _where_ARRAYREF { # 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 @@ -401,7 +403,16 @@ sub _where_ARRAYREF { 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 @@ -411,7 +422,6 @@ 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}; @@ -431,26 +441,28 @@ sub _where_HASHREF { sub _where_op_in_hash { - my ($self, $op, $v) = @_; + 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 ... ]"; + } - $op =~ /^(AND|OR|NEST)[_\d]*/i - or puke "unknown operator: -$op"; - $op = uc($1); # uppercase, remove trailing digits $self->_debug("OP(-$op) within hashref, recursing..."); $self->_SWITCH_refkind($v, { ARRAYREF => sub { - # LDNOTE : should deprecate {-or => [...]} and {-and => [...]} - # because they are misleading; the only proper way would be - # -nest => [-or => ...], -nest => [-and ...] return $self->_where_ARRAYREF($v, $op eq 'NEST' ? '' : $op); }, HASHREF => sub { if ($op eq 'OR') { - belch "-or => {...} should be -nest => [...]"; - return $self->_where_ARRAYREF([%$v], 'OR'); + return $self->_where_ARRAYREF([ map { $_ => $v->{$_} } (sort keys %$v) ], 'OR'); } else { # NEST | AND return $self->_where_HASHREF($v); @@ -492,13 +504,21 @@ sub _where_hashpair_ARRAYREF { $self->_debug("ARRAY($k) means distribute over elements"); # put apart first element if it is an operator (-and, -or) - my $op = $v[0] =~ /^-/ ? shift @v : undef; - $self->_debug("OP($op) reinjected into the distributed array") if $op; - + my $op = ( + (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix) + ? shift @v + : '' + ); my @distributed = map { {$k => $_} } @v; - unshift @distributed, $op if $op; - return $self->_recurse_where(\@distributed); + 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? @@ -508,9 +528,10 @@ sub _where_hashpair_ARRAYREF { } sub _where_hashpair_HASHREF { - my ($self, $k, $v) = @_; + my ($self, $k, $v, $logic) = @_; + $logic ||= 'and'; - my (@all_sql, @all_bind); + my ($all_sql, @all_bind); for my $op (sort keys %$v) { my $val = $v->{$op}; @@ -527,7 +548,19 @@ sub _where_hashpair_HASHREF { # 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); + my $handler = $special_op->{handler}; + if (! $handler) { + puke "No handler supplied for special operator matching $special_op->{regex}"; + } + elsif (not ref $handler) { + ($sql, @bind) = $self->$handler ($k, $op, $val); + } + elsif (ref $handler eq 'CODE') { + ($sql, @bind) = $handler->($self, $k, $op, $val); + } + else { + puke "Illegal handler for special operator matching $special_op->{regex} - expecting a method name or a coderef"; + } } else { $self->_SWITCH_refkind($val, { @@ -536,18 +569,23 @@ sub _where_hashpair_HASHREF { ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val); }, - SCALARREF => sub { # CASE: col => {op => \$scalar} + 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]} + 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 = $self->_bindtype($k, @sub_bind); + @bind = @sub_bind; + }, + + HASHREF => sub { + ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op); }, UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL" @@ -566,11 +604,10 @@ sub _where_hashpair_HASHREF { }); } - push @all_sql, $sql; + ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql; push @all_bind, @bind; } - - return $self->_join_sql_clauses('and', \@all_sql, \@all_bind); + return ($all_sql, @all_bind); } @@ -581,17 +618,24 @@ sub _where_field_op_ARRAYREF { 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 : change the distribution logic when + # 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. - my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR'; - - # distribute $op over each member of @$vals - return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic); + # 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 { @@ -613,15 +657,17 @@ sub _where_hashpair_SCALARREF { 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; - @bind = $self->_bindtype($k, @bind); 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"); @@ -677,16 +723,39 @@ sub _where_UNDEF { sub _where_field_BETWEEN { my ($self, $k, $op, $vals) = @_; - ref $vals eq 'ARRAY' && @$vals == 2 - or puke "special op 'between' requires an arrayref of two values"; + (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 ($label) = $self->_convert($self->_quote($k)); - my ($placeholder) = $self->_convert('?'); - my $and = $self->_sqlcase('and'); + my ($clause, @bind, $label, $and, $placeholder); + $label = $self->_convert($self->_quote($k)); + $and = ' ' . $self->_sqlcase('and') . ' '; + $placeholder = $self->_convert('?'); $op = $self->_sqlcase($op); - my $sql = "( $label $op $placeholder $and $placeholder )"; - my @bind = $self->_bindtype($k, @$vals); + 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) } @@ -718,6 +787,7 @@ sub _where_field_IN { ARRAYREFREF => sub { # literal SQL with bind my ($sql, @bind) = @$$vals; + $self->_assert_bindval_matches_bindtype(@bind); return ("$label $op ( $sql )", @bind); }, @@ -779,7 +849,8 @@ sub _order_by_hash { my ($order) = ($key =~ /^-(desc|asc)/i) or puke "invalid key in _order_by hash : $key"; - return $self->_quote($val) ." ". $self->_sqlcase($order); + $val = ref $val eq 'ARRAY' ? $val : [$val]; + return join ', ', map { $self->_quote($_) . ' ' . $self->_sqlcase($order) } @$val; } @@ -869,6 +940,20 @@ sub _bindtype (@) { 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) = @_; @@ -963,7 +1048,35 @@ sub values { 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; + + 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 { @@ -979,13 +1092,13 @@ sub generate { my $r = ref $v; my $label = $self->_quote($k); if ($r eq 'ARRAY') { - # SQL included for values - my @bind = @$v; - my $sql = shift @bind; + # literal SQL with bind + my ($sql, @bind) = @$v; + $self->_assert_bindval_matches_bindtype(@bind); push @sqlq, "$label = $sql"; - push @sqlv, $self->_bindtype($k, @bind); + push @sqlv, @bind; } elsif ($r eq 'SCALAR') { - # embedded literal SQL + # literal SQL without bind push @sqlq, "$label = $$v"; } else { push @sqlq, "$label = ?"; @@ -997,11 +1110,12 @@ sub generate { # 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') { + 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 { @@ -1254,12 +1368,15 @@ the huge section on L 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>. +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 = ( @@ -1267,7 +1384,7 @@ array of the form: 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' @@ -1281,10 +1398,10 @@ Which will change the above C to: WHERE event_date >= '2/13/99' AND event_date <= '4/24/03' The logic can also be changed locally by inserting -an extra first element in the array : +a modifier in front of an arrayref : - @where = (-and => event_date => {'>=', '2/13/99'}, - event_date => {'<=', '4/24/03'} ); + @where = (-and => [event_date => {'>=', '2/13/99'}, + event_date => {'<=', '4/24/03'} ]); See the L section for explanations. @@ -1354,6 +1471,10 @@ are or are not included. You could wrap that above C loop in a simple sub called C or something and reuse it repeatedly. You still get a layer of abstraction over manual SQL specification. +Note that if you set L to C, the C<\[$sql, @bind]> +construct (see L) +will expect the bind values in this format. + =item quote_char This is the character that a table or column name will be quoted @@ -1565,10 +1686,10 @@ This simple code will create the following: $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )"; @bind = ('nwiger', 'assigned', 'in-progress', 'pending'); -An empty arrayref will be considered a logical false and -will generate 0=1. +A field associated to an empty arrayref will be considered a +logical false and will generate 0=1. -=head2 Key-value pairs +=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: @@ -1585,19 +1706,9 @@ Which would generate: To test against multiple values, just enclose the values in an arrayref: - status => { '!=', ['assigned', 'in-progress', 'pending'] }; - -Which would give you: - - "WHERE status != ? AND status != ? AND status != ?" - -Notice that since the operator was recognized as being a 'negative' -operator, the arrayref was interpreted with 'AND' logic (because -of Morgan's laws). By contrast, the reverse - status => { '=', ['assigned', 'in-progress', 'pending'] }; -would generate : +Which would give you: "WHERE status = ? OR status = ? OR status = ?" @@ -1685,29 +1796,6 @@ Here is a quick list of equivalencies, since there is some overlap: 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' ], - ); - -If you need several nested subexpressions, you can number -the C<-nest> branches : - - my %where = ( - user => 'nwiger', - -nest1 => ..., - -nest2 => ..., - ... - ); =head2 Special operators : IN, BETWEEN, etc. @@ -1728,6 +1816,12 @@ Which would generate: The reverse operator C<-not_in> generates SQL C 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: @@ -1745,7 +1839,7 @@ Would give you: These are the two builtin "special operators"; but the list can be expanded : see section L below. -=head2 Nested conditions +=head2 Nested conditions, -and/-or prefixes So far, we've seen how multiple conditions are joined with a top-level C. We can change this by putting the different conditions we want in @@ -1768,15 +1862,32 @@ This data structure would create the following: 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 => [ user => 'nwiger', -nest => [ - ["-and", workhrs => {'>', 20}, geo => 'ASIA' ], - ["-and", workhrs => {'<', 50}, geo => 'EURO' ] + -and => [workhrs => {'>', 20}, geo => 'ASIA' ], + -and => [workhrs => {'<', 50}, geo => 'EURO' ] ], ], ); @@ -1787,6 +1898,37 @@ That would yield: ( ( workhrs > ? AND geo = ? ) OR ( workhrs < ? AND geo = ? ) ) ) + +=head2 Algebraic inconsistency, for historical reasons + +C: when connecting several conditions, the C<-and->|C<-or> +operator goes C of the nested structure; whereas when connecting +several constraints on one column, the C<-and> operator goes +C 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 @@ -1847,6 +1989,17 @@ 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. That means that if you set L to C, you must +provide the bind values in the C<< [ column_meta => value ] >> format, where +C is an opaque scalar value; most commonly the column name, but +you can use any scalar value (including references and blessed references), +L will simply pass it through intact. So if C is set +to C 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 : @@ -1953,30 +2106,45 @@ 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 + 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 - [ | - {-asc => 'colA'}, | ORDER BY colA ASC, colB DESC - {-desc => 'colB'} | - ] | - [colA => {-asc => 'colB'}] | ORDER BY colA, colB ASC - ========================================================== + | + \'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 $sqlmaker = SQL::Abstract->new(special_ops => [ - {regex => qr/.../, + { + regex => qr/.../, handler => sub { my ($self, $field, $op, $arg) = @_; ... - }, + }, + }, + { + regex => qr/.../, + handler => 'method_name', }, ]); @@ -1989,12 +2157,13 @@ For example : WHERE MATCH(field) AGAINST (?, ?) Special operators IN and BETWEEN are fairly standard and therefore -are builtin within C. For other operators, -like the MATCH .. AGAINST example above which is -specific to MySQL, you can write your own operator handlers : -supply a C argument to the C method. -That argument takes an arrayref of operator definitions; -each operator definition is a hashref with two entries +are builtin within C (as the overridable methods +C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators, +like the MATCH .. AGAINST example above which is specific to MySQL, +you can write your own operator handlers - supply a C +argument to the C method. That argument takes an arrayref of +operator definitions; each operator definition is a hashref with two +entries: =over @@ -2004,10 +2173,24 @@ the regular expression to match the operator =item handler -coderef that will be called when meeting that operator -in the input tree. The coderef will be called with -arguments C<< ($self, $field, $op, $arg) >>, and -should return a C<< ($sql, @bind) >> structure. +Either a coderef or a plain scalar method name. In both cases +the expected return is C<< ($sql, @bind) >>. + +When supplied with a method name, it is simply called on the +L object as: + + $self->$method_name ($field, $op, $arg) + + Where: + + $op is the part that matched the handler regex + $field is the LHS of the operator + $arg is the RHS + +When supplied with a coderef, it is called as: + + $coderef->($self, $field, $op, $arg) + =back @@ -2119,10 +2302,6 @@ support for the { operator => \["...", @bind] } construct (to embed literal SQL =item * -added -nest1, -nest2 or -nest_1, -nest_2, ... - -=item * - optional support for L =item * @@ -2132,21 +2311,12 @@ defensive programming : check arguments =item * fixed bug with global logic, which was previously implemented -through global variables yielding side-effects. Prior versons would +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 * - -C<-and> / C<-or> operators are no longer accepted -in the middle of an arrayref : they are -only admitted if in first position. - -=item * - -changed logic for distributing an op over arrayrefs =item * @@ -2182,6 +2352,7 @@ so I have no idea who they are! But the people I do know are: 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! @@ -2200,6 +2371,8 @@ While not an official support venue, C makes heavy use of C, and as such list members there are very familiar with how to create queries. +=head1 LICENSE + This module is free software; you may copy this under the terms of the GNU General Public License, or the Artistic License, copies of which should have accompanied your Perl kit.