compiler.py 文件源码

def compile_zdb_query(element, compiler, **kw):
    query = []
    tables = set()
    format_args = []
    limit = ""

    for i, c in enumerate(element.clauses):
        add_to_query = True

        if isinstance(c, BinaryExpression):
            tables.add(c.left.table.name)
        elif isinstance(c, BindParameter):
            if isinstance(c.value, str):
                pass
            elif isinstance(c.value, DeclarativeMeta):
                if i > 0:
                    raise ValueError("Table can be specified only as first param")
                tables.add(c.value.__tablename__)
                add_to_query = False
        elif isinstance(c, BooleanClauseList):
            pass
        elif isinstance(c, Column):
            pass
        else:
            raise ValueError("Unsupported filter")

        if add_to_query:
            query.append(compile_clause(c, compiler, tables, format_args))

    if not tables:
        raise ValueError("No filters passed")
    elif len(tables) > 1:
        raise ValueError("Different tables passed")
    else:
        table = tables.pop()

    if hasattr(element, "_zdb_order_by") and isinstance(element._zdb_order_by, (UnaryExpression, ZdbScore)):
        limit = compile_limit(order_by=element._zdb_order_by,
                              offset=element._zdb_offset,
                              limit=element._zdb_limit)

    sql = "zdb(\'%s\', ctid) ==> " % table
    if format_args and isinstance(format_args, list):
        sql += "\'%sformat(\'%s\', %s)\'" % (
            limit,
            " and ".join(query),
            ", ".join(format_args)
        )
    else:
        sql += "\'%s%s\'" % (
            limit,
            " and ".join(query))
    return sql