db.py 文件源码

def select(self, tables, vars=None, what='*', where=None, order=None, group=None, 
               limit=None, offset=None, _test=False): 
        """
        Selects `what` from `tables` with clauses `where`, `order`, 
        `group`, `limit`, and `offset`. Uses vars to interpolate. 
        Otherwise, each clause can be a SQLQuery.

            >>> db = DB(None, {})
            >>> db.select('foo', _test=True)
            <sql: 'SELECT * FROM foo'>
            >>> db.select(['foo', 'bar'], where="foo.bar_id = bar.id", limit=5, _test=True)
            <sql: 'SELECT * FROM foo, bar WHERE foo.bar_id = bar.id LIMIT 5'>
        """
        if vars is None: vars = {}
        sql_clauses = self.sql_clauses(what, tables, where, group, order, limit, offset)
        clauses = [self.gen_clause(sql, val, vars) for sql, val in sql_clauses if val is not None]
        qout = SQLQuery.join(clauses)
        if _test: return qout
        return self.query(qout, processed=True)