sql - postgresql 中的 EXECUTE 语法错误

Question

我想使用 execute 执行以下查询，它与 select 完美配合，但是当我在触发器中调用它时，我收到此错误“错误:查询没有结果数据的目的地”。我试过 perform 但它不起作用。 select 中的函数在表中插入行。

select insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), s.code)
FROM "student" as s
where find_st(s.grade)>=5;

所以我想到了 EXECUTE，但我遇到了语法错误。这是我的尝试:

execute 'insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), s.code)
FROM "student" as s
where find_st(s.grade)>=5';

谁能告诉我我做错了什么？还是有其他想法可以使查询在触发器功能中起作用？提前致谢..

这是触发器:

CREATE OR REPLACE FUNCTION insert_d() 
RETURNS TRIGGER AS $$ 
BEGIN
    select insert_new_grade('title0', return3_6(0), return3_6(1), return3_6(2), s.code)
    FROM "student" as s
    where find_st(s.grade)>=5;

    return new;
END;
$$ LANGUAGE plpgsql; 

这是插入函数:

CREATE OR REPLACE FUNCTION insert_new_diploma(title0 character(100), prof0 character(11), prof1 character(11)) 
RETURNS VOID AS $$
BEGIN
    INSERT INTO "d_table"(thes0, title, grade, prof, secProf) 
    VALUES (null, title0, null, prof0, prof1);
END
$$
LANGUAGE 'plpgsql';

Answer 1

41.5.2. Executing a Command With No Result

Sometimes it is useful to evaluate an expression or SELECT query but discard the result, for example when calling a function that has side-effects but no useful result value. To do this in PL/pgSQL, use the PERFORM statement

强调我的。

内部函数将 select 更改为 perform