SQL::Abstract::Plugin::BangOverrides - (unknown subject)

NAME  SYNOPSIS  METHODS  register_extensions 

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NAME

SQL::Abstract::Plugin::BangOverrides

SYNOPSIS

$sqla−>plugin('+BangOverrides');
...
profit();

METHODS

register_extensions

Wraps all currently existing clause based statements such that when a clause of '!name' is encountered, if its value is a coderef, it's called with the original value of the 'name' clause and expected to return a replacement, and if not, it's simply used as a direct replacement.

This allows for passing data through existing systems that attempt to have their own handling for thing but whose capabilities are now superceded by SQL::Abstract, and is primarily useful to provide access to experimental feature bundles such as SQL::Abstract::Plugin::ExtraClauses.

As an example of such a thing, given an appropriate DBIC setup (see "examples/bangdbic.pl"):

$s−>storage−>sqlmaker−>plugin('+ExtraClauses')−>plugin('+BangOverrides');
my $rs2 = $s−>resultset('Foo')−>search({
−op => [ '=', { −ident => 'outer.y' }, { −ident => 'me.x' } ]
});
# (SELECT me.x, me.y, me.z FROM foo me WHERE ( outer.y = me.x ))
my $rs3 = $rs2−>search({}, {
'!from' => sub { my ($sqla, $from) = @_;
my $base = $sqla−>expand_expr({ −old_from => $from });
return [ $base, −join => [ 'wub', on => [ 'me.z' => 'wub.z' ] ] ];
}
});
# (SELECT me.x, me.y, me.z FROM foo me JOIN wub ON me.z = wub.z WHERE ( outer.y = me.x ))
my $rs4 = $rs3−>search({}, {
'!with' => [ [ qw(wub x y z) ], $s−>resultset('Bar')−>as_query ],
});
# (WITH wub(x, y, z) AS (SELECT me.a, me.b, me.c FROM bar me) SELECT me.x, me.y, me.z FROM foo me JOIN wub ON me.z = wub.z WHERE ( outer.y = me.x ))
my $rs5 = $rs−>search({}, { select => [ { −coalesce => [ { −ident => 'x' }, { −value => 7 } ] } ] });
# (SELECT −COALESCE( −IDENT( x ), −VALUE( 7 ) ) FROM foo me WHERE ( z = ? ))
my $rs6 = $rs−>search({}, { '!select' => [ { −coalesce => [ { −ident => 'x' }, { −value => 7 } ] } ] });
# (SELECT COALESCE(x, ?) FROM foo me WHERE ( z = ? ))

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