NAME

       SQL::Translator::Schema::Constraint - SQL::Translator constraint object

SYNOPSIS

         use SQL::Translator::Schema::Constraint;
         my $constraint = SQL::Translator::Schema::Constraint->new(
             name   => 'foo',
             fields => [ id ],
             type   => PRIMARY_KEY,
         );

DESCRIPTION

       "SQL::Translator::Schema::Constraint" is the constraint object.

METHODS

   new
       Object constructor.

         my $schema           =  SQL::Translator::Schema::Constraint->new(
             table            => $table,        # table to which it belongs
             type             => 'foreign_key', # type of table constraint
             name             => 'fk_phone_id', # name of the constraint
             fields           => 'phone_id',    # field in the referring table
             reference_fields => 'phone_id',    # referenced field
             reference_table  => 'phone',       # referenced table
             match_type       => 'full',        # how to match
             on_delete        => 'cascade',     # what to do on deletes
             on_update        => '',            # what to do on updates
         );

   deferrable
       Get or set whether the constraint is deferrable.  If not defined, then returns "1."  The
       argument is evaluated by Perl for True or False, so the following are equivalent:

         $deferrable = $field->deferrable(0);
         $deferrable = $field->deferrable('');
         $deferrable = $field->deferrable('0');

   expression
       Gets and set the expression used in a CHECK constraint.

         my $expression = $constraint->expression('...');

   is_valid
       Determine whether the constraint is valid or not.

         my $ok = $constraint->is_valid;

   fields
       Gets and set the fields the constraint is on.  Accepts a string, list or arrayref; returns
       an array or array reference.  Will unique the field names and keep them in order by the
       first occurrence of a field name.

       The fields are returned as Field objects if they exist or as plain names if not. (If you
       just want the names and want to avoid the Field's overload magic use "field_names").

       Returns undef or an empty list if the constraint has no fields set.

         $constraint->fields('id');
         $constraint->fields('id', 'name');
         $constraint->fields( 'id, name' );
         $constraint->fields( [ 'id', 'name' ] );
         $constraint->fields( qw[ id name ] );

         my @fields = $constraint->fields;

   field_names
       Read-only method to return a list or array ref of the field names. Returns undef or an
       empty list if the constraint has no fields set. Useful if you want to avoid the overload
       magic of the Field objects returned by the fields method.

         my @names = $constraint->field_names;

   match_type
       Get or set the constraint's match_type.  Only valid values are "full" "partial" and
       "simple"

         my $match_type = $constraint->match_type('FULL');

   name
       Get or set the constraint's name.

         my $name = $constraint->name('foo');

   options
       Gets or adds to the constraints's options (e.g., "INITIALLY IMMEDIATE").  Returns an array
       or array reference.

         $constraint->options('NORELY');
         my @options = $constraint->options;

   on_delete
       Get or set the constraint's "on delete" action.

         my $action = $constraint->on_delete('cascade');

   on_update
       Get or set the constraint's "on update" action.

         my $action = $constraint->on_update('no action');

   reference_fields
       Gets and set the fields in the referred table.  Accepts a string, list or arrayref;
       returns an array or array reference.

         $constraint->reference_fields('id');
         $constraint->reference_fields('id', 'name');
         $constraint->reference_fields( 'id, name' );
         $constraint->reference_fields( [ 'id', 'name' ] );
         $constraint->reference_fields( qw[ id name ] );

         my @reference_fields = $constraint->reference_fields;

   reference_table
       Get or set the table referred to by the constraint.

         my $reference_table = $constraint->reference_table('foo');

   table
       Get or set the constraint's table object.

         my $table = $field->table;

   type
       Get or set the constraint's type.

         my $type = $constraint->type( PRIMARY_KEY );

   equals
       Determines if this constraint is the same as another

         my $isIdentical = $constraint1->equals( $constraint2 );

AUTHOR

       Ken Youens-Clark <kclark@cpan.org>.