postgresql - 迭代函数返回的表

Question

我已经声明了两个函数（duplicate_iofs 和 duplicate_ioftypes），它们在执行 INSERT 操作后都返回一个表：

CREATE OR REPLACE FUNCTION duplicate_iofs(IN iof_group_src_id integer, IN iof_group_dst_id integer)
    RETURNS TABLE(src_id integer, new_id integer) AS $$
BEGIN
    -- DO INSERT REQUESTS
END;

CREATE OR REPLACE FUNCTION duplicate_ioftypes(IN iof_group_src_id integer, IN iof_group_dst_id integer)
    RETURNS TABLE(src_id integer, new_id integer) AS $$
BEGIN
    -- DO INSERT REQUESTS
END;

我怎样才能在第三个函数中做类似的事情：

-- 1. Call duplicate_iofs(...) and store the result table (e.g. iofs_table)

-- 2. Call duplicate_ioftypes(...) and store the result table (e.g. ioftypes_table).

-- 3. Iterate through 'iofs_table' and 'ioftypes_table' with nested loops :
FOR iof_row IN SELECT * FROM iofs_table LOOP
    FOR ioftype_row IN SELECT * FROM ioftypes_table LOOP
        -- DO SOMETHING
    END LOOP;
END LOOP; 

注意：duplicate_iofs() 和 duplicate_ioftypes() 必须只调用一次，因此不得在嵌套循环中调用。

Answer 1

你可以尝试这样的事情：

DECLARE
    curs_iof CURSOR FOR SELECT * FROM iofs_table;
    curs_ioftype CURSOR FOR SELECT * FROM ioftypes_table;
BEGIN
    OPEN SCROLL curs_iof;
    OPEN SCROLL curs_ioftype;

    FETCH curs_iof INTO iof_row;
    WHILE FOUND LOOP
        FETCH FIRST FROM curs_ioftype INTO ioftype_row;
        WHILE FOUND LOOP

            -- DO SOMETHING

            FETCH curs_ioftype INTO ioftype_row;
        END LOOP;
        FETCH curs_iof INTO iof_row;
    END LOOP;

    CLOSE curs_iof;
    CLOSE curs_ioftype;
END;

详情在这里。