Question

我是一名MySQL新手并且一直在尝试创建存储过程。以下代码返回错误Error Code: 1172. Result consisted of more than one row。我究竟做错了什么？（我正在使用MySQL工作台）

CREATE DEFINER=`root`@`localhost` PROCEDURE `season_private_league_user`(
IN user_id INT,
OUT league_name VARCHAR(25),
OUT host_user VARCHAR(30))
BEGIN

    DECLARE userteamid INT;
    DECLARE var_league_name VARCHAR(25);
    DECLARE var_host_user VARCHAR(30);

    # Retrieve user team from user_id
    SELECT CS_USER_TEAMS_ID INTO userteamid
    FROM classicseasonmodel_classicseasonuserteam
    WHERE user_id = user_id;

    #LEAGUE NAME
    SELECT classicseasonmodel_classicseasonprivateleague.private_league_name INTO var_league_name
    FROM   classicseasonmodel_classicseasonuserteamprivateleague
    INNER JOIN classicseasonmodel_classicseasonprivateleague
    ON classicseasonmodel_classicseasonuserteamprivateleague.private_league_id=classicseasonmodel_classicseasonprivateleague.CS_PRIVATE_LEAGUE_ID
    WHERE  user_team_id = userteamid;

    #HOST_USER
    SELECT classicseasonmodel_classicseasonprivateleague.host_user_id INTO var_host_user
    FROM   classicseasonmodel_classicseasonuserteamprivateleague
    INNER JOIN classicseasonmodel_classicseasonprivateleague
    ON classicseasonmodel_classicseasonuserteamprivateleague.private_league_id=classicseasonmodel_classicseasonprivateleague.CS_PRIVATE_LEAGUE_ID
    WHERE  user_team_id = userteamid;

    SET league_name = var_league_name;
    SET host_user = var_host_user;

END

CALL season_private_league_user(2, @league_name, @host_user); SELECT @league_name AS league_name; SELECT @host_user AS host_user;

Answer 1

将结果存储在变量中的存储过程的SELECT之一返回多行，该行返回此错误。这样，您只能在变量中存储单个值，而不能存储多个值。

您可以阅读SELECT ... INTO语句here。对你来说最有趣的部分是：

将所选值分配给变量。的数量变量必须与列数匹配。查询应该返回一个单排。如果查询未返回任何行，则会显示带有错误代码的警告发生1329（无数据），变量值保持不变。如果查询返回多行，发生错误1172（结果包含不止一行）。如果声明可能的话检索多行，您可以使用LIMIT 1将结果集限制为一行。

Answer 2

您的列名和参数名称相同。重命名输入参数并将命令更改为：

SELECT CS_USER_TEAMS_ID INTO userteamid
FROM classicseasonmodel_classicseasonuserteam
WHERE user_id = @user_id;

MySQL - 结果由多行组成

2 个答案: