has sqla => (
is => 'ro', init_arg => undef,
handles => [ qw(
- expand_expr expand_maybe_list_expr render_aqt join_query_parts
+ expand_expr render_aqt join_query_parts
) ],
);
clause_expanders => [
"select.from", '_expand_from_list',
'select.group_by'
- => sub { $_[0]->expand_maybe_list_expr($_[2], -ident) },
+ => sub { $_[0]->expand_expr({ -list => $_[2] }, -ident) },
'select.having'
=> sub { $_[0]->expand_expr($_[2]) },
'update.from' => '_expand_from_list',
clause_renderer => [
'select.setop' => sub { $_[0]->render_aqt($_[2]) }
],
- expander => [ map +($_ => '_expand_setop'), qw(union intersect except) ],
+ expander => [
+ map +($_ => '_expand_setop', "${_}_all" => '_expand_setop'), qw(union intersect except) ],
renderer => [ map +($_ => '_render_setop'), qw(union intersect except) ],
);
my ($self, undef, $vv, $k) = @_;
my @vv = (ref($vv) eq 'ARRAY' ? @$vv : $vv);
my $ik = $self->expand_expr($k, -ident);
- return +{ -as => [ $ik, $self->expand_expr($vv[0], -alias) ] }
+ return +{ -as => [ $ik, $self->expand_expr($vv[0], -ident) ] }
if @vv == 1 and ref($vv[0]) eq 'HASH';
my @as = map $self->expand_expr($_, -ident), @vv;
- return { -as => [ $ik, { -alias => \@as } ] };
+ return { -as => [ $ik, $self->expand_expr({ -alias => \@as }) ] };
}
sub _render_as {
if (ref($args) eq 'HASH' and my $alias = $args->{-alias}) {
$args = $alias;
}
- +{ -alias => [
- map $self->expand_expr($_, -ident),
- ref($args) eq 'ARRAY' ? @{$args} : $args
- ]
- }
+ my @parts = map $self->expand_expr($_, -ident),
+ ref($args) eq 'ARRAY' ? @{$args} : $args;
+ return $parts[0] if @parts == 1;
+ return { -alias => \@parts };
}
sub _expand_with {
sub _expand_setop {
my ($self, $setop, $args) = @_;
+ my $is_all = $setop =~ s/_all$//;
+{ "-${setop}" => {
- %$args,
- queries => [ map $self->expand_expr($_), @{$args->{queries}} ],
+ ($is_all ? (type => 'all') : ()),
+ (ref($args) eq 'ARRAY'
+ ? (queries => [ map $self->expand_expr($_), @$args ])
+ : (
+ %$args,
+ queries => [ map $self->expand_expr($_), @{$args->{queries}} ]
+ )
+ ),
} };
}
my $sqla = SQL::Abstract->new;
SQL::Abstract::ExtraClauses->apply_to($sqla);
+=head1 WARNING
+
+This module is basically a nursery for things that seem like a good idea
+to live in until we figure out if we were right about that.
+
=head1 METHODS
=head2 apply_to
{ foo => { -as => 'bar' } }
# aqt
- { -as =>
- [
- { -ident => [ 'foo' ] },
- { -alias => [ { -ident => [ 'bar' ] } ] },
- ]
- }
+ { -as => [ { -ident => [ 'foo' ] }, { -ident => [ 'bar' ] } ] }
# query
foo AS bar
# aqt
{ -join => {
- from => { -as => [
- { -ident => [ 't1' ] },
- { -alias => [ { -ident => [ 'table_one' ] } ] },
- ] },
+ from =>
+ {
+ -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+ },
on => { -op => [
'=', { -ident => [ 'table_one', 'x' ] },
{ -ident => [ 't2', 'x' ] },
# aqt
{ -join => {
- from => { -as => [
- { -ident => [ 't1' ] },
- { -alias => [ { -ident => [ 'table_one' ] } ] },
- ] },
+ from =>
+ {
+ -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+ },
to => { -ident => [ 't2' ] },
type => undef,
using =>
x LEFT JOIN ( y LEFT JOIN z )
[]
+=head2 setops
+
+Expanders are provided for union, union_all, intersect, intersect_all,
+except and except_all, and each takes an arrayref of queries:
+
+ # expr
+ { -union => [
+ { -select => { _ => { -value => 1 } } },
+ { -select => { _ => { -value => 2 } } },
+ ] }
+
+ # aqt
+ { -union => { queries => [
+ { -select =>
+ { select => { -op => [ ',', { -bind => [ undef, 1 ] } ] } }
+ },
+ { -select =>
+ { select => { -op => [ ',', { -bind => [ undef, 2 ] } ] } }
+ },
+ ] } }
+
+ # query
+ (SELECT ?) UNION (SELECT ?)
+ [ 1, 2 ]
+
+ # expr
+ { -union_all => [
+ { -select => { _ => { -value => 1 } } },
+ { -select => { _ => { -value => 2 } } },
+ { -select => { _ => { -value => 1 } } },
+ ] }
+
+ # aqt
+ { -union => {
+ queries => [
+ { -select =>
+ { select => { -op => [ ',', { -bind => [ undef, 1 ] } ] } }
+ },
+ { -select =>
+ { select => { -op => [ ',', { -bind => [ undef, 2 ] } ] } }
+ },
+ { -select =>
+ { select => { -op => [ ',', { -bind => [ undef, 1 ] } ] } }
+ },
+ ],
+ type => 'all',
+ } }
+
+ # query
+ (SELECT ?) UNION ALL (SELECT ?) UNION ALL (SELECT ?)
+ [ 1, 2, 1 ]
+
+=head1 STATEMENT EXTENSIONS
+
+=head2 group by clause for select
+
+Expanded as a list with an ident default:
+
+ # expr
+ { -select => { group_by => [ 'foo', 'bar' ] } }
+
+ # aqt
+ { -select => { group_by =>
+ {
+ -op => [ ',', { -ident => [ 'foo' ] }, { -ident => [ 'bar' ] } ]
+ }
+ } }
+
+ # query
+ GROUP BY foo, bar
+ []
+
+=head2 having clause for select
+
+Basic expr, just like where, given having is pretty much post-group-by
+where clause:
+
+ # expr
+ { -select =>
+ { having => { '>' => [ { -count => { -ident => 'foo' } }, 3 ] } }
+ }
+
+ # aqt
+ { -select => { having => { -op => [
+ '>', { -func => [ 'count', { -ident => [ 'foo' ] } ] },
+ { -bind => [ undef, 3 ] },
+ ] } } }
+
+ # query
+ HAVING COUNT(foo) > ?
+ [ 3 ]
+
+=head2 setop clauses
+
+If a select query contains a clause matching any of the setop node types,
+clauses that appear before the setop would in the resulting query are
+gathered together and moved into an inner select node:
+
+ # expr
+ { -select => {
+ _ => '*',
+ from => 'foo',
+ order_by => 'baz',
+ union =>
+ {
+ -select => { _ => '*', from => 'bar', where => { thing => 1 } }
+ },
+ where => { thing => 1 },
+ } }
+
+ # aqt
+ { -select => {
+ order_by => { -op => [ ',', { -ident => [ 'baz' ] } ] },
+ setop => { -union => { queries => [
+ { -select => {
+ from => { -ident => [ 'foo' ] },
+ select => { -op => [ ',', { -ident => [ '*' ] } ] },
+ where => { -op => [
+ '=', { -ident => [ 'thing' ] },
+ { -bind => [ 'thing', 1 ] },
+ ] },
+ } }, ] },
+ { -select => {
+ from => { -ident => [ 'bar' ] },
+ select => { -op => [ ',', { -ident => [ '*' ] } ] },
+ where => { -op => [
+ '=', { -ident => [ 'thing' ] },
+ { -bind => [ 'thing', 1 ] },
+ } },
+ ] } },
+ } }
+
+ # query
+ (SELECT * FROM foo WHERE thing = ?) UNION (
+ SELECT * FROM bar WHERE thing = ?
+ )
+ ORDER BY baz
+ [ 1, 1 ]
+
+=head2 update from clause
+
+Some databases allow an additional FROM clause to reference other tables
+for the data to update; this clause is expanded as a normal from list, check
+your database for what is and isn't allowed in practice.
+
+ # expr
+ { -update => {
+ _ => 'employees',
+ from => 'accounts',
+ set => { sales_count => { sales_count => { '+' => \1 } } },
+ where => {
+ 'accounts.name' => { '=' => \"'Acme Corporation'" },
+ 'employees.id' => { -ident => 'accounts.sales_person' },
+ },
+ } }
+
+ # aqt
+ { -update => {
+ from => { -ident => [ 'accounts' ] },
+ set => { -op => [
+ ',', { -op => [
+ '=', { -ident => [ 'sales_count' ] }, { -op => [
+ '+', { -ident => [ 'sales_count' ] },
+ { -literal => [ 1 ] },
+ ] },
+ ] },
+ ] },
+ target => { -ident => [ 'employees' ] },
+ where => { -op => [
+ 'and', { -op => [
+ '=', { -ident => [ 'accounts', 'name' ] },
+ { -literal => [ "'Acme Corporation'" ] },
+ ] }, { -op => [
+ '=', { -ident => [ 'employees', 'id' ] },
+ { -ident => [ 'accounts', 'sales_person' ] },
+ ] },
+ ] },
+ } }
+
+ # query
+ UPDATE employees SET sales_count = sales_count + 1 FROM accounts
+ WHERE (
+ accounts.name = 'Acme Corporation'
+ AND employees.id = accounts.sales_person
+ )
+ []
+
+=head2 delete using clause
+
+Some databases allow an additional USING clause to reference other tables
+for the data to update; this clause is expanded as a normal from list, check
+your database for what is and isn't allowed in practice.
+
+ # expr
+ { -delete => {
+ from => 'x',
+ using => 'y',
+ where => { 'x.id' => { -ident => 'y.x_id' } },
+ } }
+
+ # aqt
+ { -delete => {
+ target => { -op => [ ',', { -ident => [ 'x' ] } ] },
+ using => { -ident => [ 'y' ] },
+ where => { -op => [
+ '=', { -ident => [ 'x', 'id' ] },
+ { -ident => [ 'y', 'x_id' ] },
+ ] },
+ } }
+
+ # query
+ DELETE FROM x USING y WHERE x.id = y.x_id
+ []
+
+=head2 insert rowvalues and select clauses
+
+rowvalues and select are shorthand for
+
+ { from => { -select ... } }
+
+and
+
+ { from => { -values ... } }
+
+respectively:
+
+ # expr
+ { -insert =>
+ { into => 'numbers', rowvalues => [ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ] ] }
+ }
+
+ # aqt
+ { -insert => {
+ from => { -values => [
+ { -row =>
+ [ { -bind => [ undef, 1 ] }, { -bind => [ undef, 2 ] } ]
+ },
+ { -row =>
+ [ { -bind => [ undef, 3 ] }, { -bind => [ undef, 4 ] } ]
+ },
+ { -row =>
+ [ { -bind => [ undef, 5 ] }, { -bind => [ undef, 6 ] } ]
+ },
+ ] },
+ target => { -ident => [ 'numbers' ] },
+ } }
+
+ # query
+ INSERT INTO numbers VALUES (?, ?), (?, ?), (?, ?)
+ [ 1, 2, 3, 4, 5, 6 ]
+
+ # expr
+ { -insert =>
+ { into => 'numbers', select => { _ => '*', from => 'old_numbers' } }
+ }
+
+ # aqt
+ { -insert => {
+ from => { -select => {
+ from => { -ident => [ 'old_numbers' ] },
+ select => { -op => [ ',', { -ident => [ '*' ] } ] },
+ } },
+ target => { -ident => [ 'numbers' ] },
+ } }
+
+ # query
+ INSERT INTO numbers SELECT * FROM old_numbers
+ []
+
+=head2 with and with_recursive clauses
+
+These clauses are available on select/insert/update/delete queries; check
+your database for applicability (e.g. mysql supports all four but mariadb
+only select).
+
+The value should be an arrayref of name/query pairs:
+
+ # expr
+ { -select => {
+ from => 'foo',
+ select => '*',
+ with => [ 'foo', { -select => { select => \1 } } ],
+ } }
+
+ # aqt
+ { -select => {
+ from => { -ident => [ 'foo' ] },
+ select => { -op => [ ',', { -ident => [ '*' ] } ] },
+ with => { queries => [ [
+ { -ident => [ 'foo' ] }, { -select =>
+ { select => { -op => [ ',', { -literal => [ 1 ] } ] } }
+ },
+ ] ] },
+ } }
+
+ # query
+ WITH foo AS (SELECT 1) SELECT * FROM foo
+ []
+
+A more complete example (designed for mariadb, (ab)using the fact that
+mysqloids materialise subselects in FROM into an unindexed temp table to
+circumvent the restriction that you can't select from the table you're
+currently updating:
+
+ # expr
+ { -update => {
+ _ => [
+ 'tree_table', -join => {
+ as => 'tree',
+ on => { 'tree.id' => 'tree_with_path.id' },
+ to => { -select => {
+ from => 'tree_with_path',
+ select => '*',
+ with_recursive => [
+ [ 'tree_with_path', 'id', 'parent_id', 'path' ],
+ { -select => {
+ _ => [
+ 'id', 'parent_id', { -as => [
+ { -cast => { -as => [ 'id', 'char', 255 ] } },
+ 'path',
+ ] } ],
+ from => 'tree_table',
+ union_all => { -select => {
+ _ => [
+ 't.id', 't.parent_id', { -as => [
+ { -concat => [ 'r.path', \"'/'", 't.id' ] },
+ 'path',
+ ] },
+ ],
+ from => [
+ 'tree_table', -as => 't', -join => {
+ as => 'r',
+ on => { 't.parent_id' => 'r.id' },
+ to => 'tree_with_path',
+ },
+ ],
+ } },
+ where => { parent_id => undef },
+ } },
+ ],
+ } },
+ },
+ ],
+ set => { path => { -ident => [ 'tree', 'path' ] } },
+ } }
+
+ # query
+ UPDATE
+ tree_table JOIN
+ (
+ WITH RECURSIVE
+ tree_with_path(id, parent_id, path) AS (
+ (
+ SELECT id, parent_id, CAST(id AS char(255)) AS path
+ FROM tree_table WHERE parent_id IS NULL
+ ) UNION ALL (
+ SELECT t.id, t.parent_id, CONCAT(r.path, '/', t.id) AS path
+ FROM
+ tree_table AS t JOIN tree_with_path AS r ON
+ t.parent_id = r.id
+ )
+ )
+ SELECT * FROM tree_with_path
+ ) AS tree
+ ON tree.id = tree_with_path.id
+ SET path = tree.path
+ []
+
=cut
projects / scpubgit/Q-Branch.git / blobdiff