+=item sql_alter_constraints PROTOTYPE_TABLE, [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
+
+Returns a list of SQL statements to alter this table's constraints (foreign
+keys) so that they are identical to the provided table, also a
+DBIx::DBSchema::Table object.
+
+The data source can be specified by passing an open DBI database handle, or by
+passing the DBI data source name, username and password.
+
+Although the username and password are optional, it is best to call this method
+with a database handle or data source including a valid username and password -
+a DBI connection will be opened and used to check the database version as well
+as for more reliable quoting and type mapping. Note that the database
+connection will be used passively, B<not> to actually run the CREATE
+statements.
+
+If passed a DBI data source (or handle) such as `DBI:mysql:database' or
+`DBI:Pg:dbname=database', will use syntax specific to that database engine.
+Currently supported databases are MySQL and PostgreSQL.
+
+If not passed a data source (or handle), or if there is no driver for the
+specified database, will attempt to use generic SQL syntax.
+
+=cut
+
+sub sql_alter_constraints {
+ my($self, $opt, $new, $dbh) = ( shift, _parse_opt(\@_), shift, _dbh(@_) );
+
+ my $driver = _load_driver($dbh);
+
+ my $table = $self->name;
+
+ my @at = ();
+
+ # foreign keys (add)
+ foreach my $foreign_key ( $new->foreign_keys ) {
+
+ next if grep $foreign_key->cmp($_), $self->foreign_keys;
+
+ push @at, 'ADD '. $foreign_key->sql_foreign_key;
+ }
+
+ #foreign keys (drop)
+ foreach my $foreign_key ( $self->foreign_keys ) {
+
+ next if grep $foreign_key->cmp($_), $new->foreign_keys;
+ next unless $foreign_key->constraint;
+
+ push @at, 'DROP CONSTRAINT '. $foreign_key->constraint;
+ }
+
+ return () unless @at;
+ (
+ 'ALTER TABLE '. $self->name. ' '. join(",\n ", @at)
+ );
+
+}
+
projects / DBIx-DBSchema.git / blobdiff