如何在Postgres函数中使用WITH？

Question

在函数中如何用as编写？ 我想编写一个递归函数来计算汽车的重量。 它给了我这样的错误：错误：“ WITH”或附近的语法错误

create or replace function aggregateWeight(p integer)
returns int as
$$ 
begin
    if p in (select p.pid
        from parts p) then
        return (select p.weight
                from parts p)
    else
        return
        WITH RECURSIVE included_parts(pid, sid, quantity) AS (
        SELECT ps.pid, ps.sid, ps.quantity
        FROM partSubPart ps
        UNION ALL
        SELECT pr.pid, ps.sid, pr.quantity*ps.quantity
        FROM included_parts pr, partSubPart ps
        WHERE ps.pid = pr.sid
        )
        SELECT sum(pr.quantity*p.weight)
        FROM included_parts pr, parts p
        where pr.sid in (select p.pid from parts p)
        GROUP BY pid;
end;
$$ language sql;

Answer 1

尝试用括号将查询括起来。

您还缺少END IF; 在ELSE 。