Cake\Database\Schema\PostgresSchema::describeColumnSql PHP Method

    public function describeColumnSql($tableName, $config)
    {
        $sql = 'SELECT DISTINCT table_schema AS schema,
            column_name AS name,
            data_type AS type,
            is_nullable AS null, column_default AS default,
            character_maximum_length AS char_length,
            c.collation_name,
            d.description as comment,
            ordinal_position,
            pg_get_serial_sequence(attr.attrelid::regclass::text, attr.attname) IS NOT NULL AS has_serial
        FROM information_schema.columns c
        INNER JOIN pg_catalog.pg_namespace ns ON (ns.nspname = table_schema)
        INNER JOIN pg_catalog.pg_class cl ON (cl.relnamespace = ns.oid AND cl.relname = table_name)
        LEFT JOIN pg_catalog.pg_index i ON (i.indrelid = cl.oid AND i.indkey[0] = c.ordinal_position)
        LEFT JOIN pg_catalog.pg_description d on (cl.oid = d.objoid AND d.objsubid = c.ordinal_position)
        LEFT JOIN pg_catalog.pg_attribute attr ON (cl.oid = attr.attrelid AND column_name = attr.attname)
        WHERE table_name = ? AND table_schema = ? AND table_catalog = ?
        ORDER BY ordinal_position';
        $schema = empty($config['schema']) ? 'public' : $config['schema'];
        return [$sql, [$tableName, $schema, $config['database']]];
    }