public static function getColumns(DB\Table $table)
{
//using namespace for the table identifier as there might be same name DBs on different servers
$namespace = $table->getDatabase()->getNamespace();
if (!isset(self::$_column_cache[$namespace])) {
self::$_column_cache[$namespace] = array();
$column_sql = 'SELECT "table_name", "column_name", "column_default", "is_nullable", "data_type" ' . 'FROM "information_schema"."columns" WHERE "table_schema" = ? ORDER BY ordinal_position';
$column_stmt = $table->getDatabase()->getConnection()->prepare($column_sql);
$column_stmt->execute(array($table->getDatabase()->getSchema()));
while ($column_row = $column_stmt->fetch()) {
self::$_column_cache[$namespace][$column_row['table_name']][] = $column_row;
}
}
$columns = array();
//may not be any columns
if (isset(self::$_column_cache[$namespace][$table->getName()])) {
foreach (self::$_column_cache[$namespace][$table->getName()] as $cached_row) {
list($default_value, $is_serial, $sequence) = self::translateSQLDefault($cached_row['column_default']);
$column = new DB\Column($table, $cached_row['column_name'], self::translateSQLNullable($cached_row['is_nullable']), self::translateSQLDataType($cached_row['data_type']), $default_value, $is_serial);
if ($sequence !== null) {
$column->setSequenceName($sequence);
}
$columns[$cached_row['column_name']] = $column;
}
}
return $columns;
}
public static function create(Column $local_column, Column $referenced_column, $constraint_name, $is_reverse_relation)
{
//This is to support multiple column foreign keys, any constraints with the same name will be treated as an additional column.
//An assumption is made in the driver that the constraint names will be unique across the table
$instance_name = sprintf('%s.%s.%s__%s', $local_column->getTable()->getDatabase()->getName(), $local_column->getTable()->getName(), $constraint_name, $is_reverse_relation ? 'reverse' : 'forward');
if (isset(self::$instances[$instance_name])) {
self::$instances[$instance_name]->addColumns($local_column, $referenced_column, $is_reverse_relation);
} else {
self::$instances[$instance_name] = new self($local_column, $referenced_column, $is_reverse_relation, $instance_name);
}
return self::$instances[$instance_name];
}
