SELECT .. INTO 返回多行 - Mysql [英] SELECT .. INTO returns more than one rows - Mysql

问题描述

我有一个基本的存储过程

i have a basic stored procedure

DECLARE user_o VARCHAR(50);

SELECT user_name INTO user_o FROM users WHERE topic_id = 54 AND entry_time BETWEEN 
2017-09-17 AND date_add( CURRENT_DATE, INTERVAL 1 DAY) ORDER BY entry_time ASC 
LIMIT 10;

这会引发错误 #1172 sql 返回多行.不知道为什么?

this throws me error #1172 sql returns more than one rows. no idea why?

我的目标是得到这个结果集

my goal is to have this result set

user_name |  user_o
  mike       mike
  liz        liz
  helen      helen
  her        her

推荐答案

这是因为您将结果INTO"插入到一个变量中，并且因为结果不止一个值，因此出现了错误.

Its because you are inserting the result 'INTO' a variable and because the result is more than a single value, hence the error.

您的限制为 10，尝试更改为 1，这将解决它，如果您想要返回多个值，那么您需要在记录集中管理这些值.

You have a limit of 10, try changing to 1, that will fix it, if you want multiple values returned then you need to manage these in a recordset.

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