Question

这是mysql存储过程，只是从select查询中打印获取的val。不确定我哪里出错，它总是打印null

DELIMITER $$
DROP PROCEDURE IF EXISTS test $$
CREATE PROCEDURE test(IN input VARCHAR(5000),OUT output VARCHAR(5000))
 BEGIN 
    DECLARE detail_id VARCHAR(128);
    DECLARE val VARCHAR(128);

    SET output = CONCAT(output, "0", ':', "Starting");

    select split_string_new(input,':', 1) into val;

    SET output = CONCAT(output, "detail_id0---",detail_id,"....");

    SET detail_id = "";

    SELECT `dtl_id` FROM detail_tbl WHERE `dtl_val` = val INTO detail_id; 
    SET output = CONCAT(output, "detail_id1---",detail_id,"....");

 END $$
DELIMITER ;

call test('123',@output);SELECT @output;

我尝试了在stackoverflow上找到的几个解决方案，只有下面和更多，但仍然不成功。任何有关这方面的帮助将不胜感激！ MySQL Stored procedure variables from SELECT statements MySql SELECT INTO Variable: returns null

Answer 1

尝试在INTO子句之前放置FROM子句。

SELECT `dtl_id` INTO detail_id FROM detail_tbl WHERE `dtl_val` = val;

选择变量不起作用

1 个答案: