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  • PostgreSQL 的 pl/pgsql 的 cannot begin/end transactions in PL/pgSQL错误

    postgres=# select FindCourse('aaaa');
    ERROR:  cannot begin/end transactions in PL/pgSQL
    HINT:  Use a BEGIN block with an EXCEPTION clause instead.
    CONTEXT:  PL/pgSQL function findcourse(character varying) line 21 at SQL statement

    出现这种错误的原因是:

    看我改后的代码:

    [postgres@lex pgsql]$ cat ./data/test.sqlCREATE OR REPLACE Function FindCourse
       ( name_in IN varchar )
       RETURNS integer LANGUAGE plpgsql AS $$
    DECLARE
        cnumber integer;
        c1 CURSOR
        FOR
           SELECT course_number, instructor
            from course_tbl
            where course_name = name_in
            FOR UPDATE;
    
    BEGIN
    
    BEGIN
    open c1;
    fetch c1 into cnumber;
    
    IF not found THEN
         cnumber := 9999;
    ELSE
         UPDATE course_tbl
            SET instructor = 'SMITH'
            WHERE CURRENT OF c1;
        COMMIT;
    END IF;
    
    close c1;
    
    EXCEPTION
    WHEN OTHERS THEN
    END;
    RETURN cnumber;
    END;$$;
    [postgres@lex pgsql]$ 

    而我之前的是:

    [postgres@lex pgsql]$ cat ./data/test.sqlCREATE OR REPLACE Function FindCourse
       ( name_in IN varchar )
       RETURNS integer LANGUAGE plpgsql AS $$
    DECLARE
        cnumber integer;
        c1 CURSOR
        FOR
           SELECT course_number, instructor
            from course_tbl
            where course_name = name_in
            FOR UPDATE;
    
    BEGIN
    
    BEGIN
    open c1;
    fetch c1 into cnumber;
    
    IF not found THEN
         cnumber := 9999;
    ELSE
         UPDATE course_tbl
            SET instructor = 'SMITH'
            WHERE CURRENT OF c1;
        COMMIT;
    END IF;
    
    close c1;
    
    EXCEPTION
    WHEN OTHERS THEN
    END;
    RETURN cnumber;
    END;$$;
    [postgres@lex pgsql]$ 

    这就是差别了。

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  • 原文地址:https://www.cnblogs.com/gaojian/p/3124278.html
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