Mysql 如何修复：错误代码：1242。子查询返回超过1行

这很好：

UPDATE users 
        SET group_id = (SELECT Prov_Current_Address_City FROM users WHERE scope IS NULL AND health_facility_id = 10) 
WHERE scope IN ('MHO', 'Mayor', 'Doctor') AND health_facility_id = 10;

有了这个，我得到了一个错误：

UPDATE users 
        SET group_id = (SELECT Prov_Current_Address_City FROM users WHERE scope IS NULL AND health_facility_id = (SELECT Prov_Current_Address_City FROM users WHERE scope IS NULL)) 
WHERE scope IN ('MHO', 'Mayor', 'Doctor') AND health_facility_id = (SELECT health_facility_id FROM users WHERE scope IS NULL);

但是这个

(SELECT Prov_Current_Address_City FROM users WHERE scope IS NULL) 

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查询正在返回许多数据。我想要实现的是更新列组id中的多行。如果没有任何其他限制城市的条件，请参见此图。 像这样做

UPDATE users 
SET group_id = (SELECT Prov_Current_Address_City 
                FROM users 
                WHERE scope IS NULL 
                 AND health_facility_id = (SELECT Prov_Current_Address_City 
                                           FROM users 
                                          WHERE scope IS NULL
                                          ORDER BY Prov_Current_Address_City
                                          Limit 1)
                ORDER BY Prov_Current_Address_City
                Limit 1) 
WHERE scope IN ('MHO', 'Mayor', 'Doctor') 
AND health_facility_id = (SELECT health_facility_id 
                          FROM users 
                          WHERE scope IS NULL
                          ORDER BY health_facility_id 
                          Limit 1);

---

当子查询返回多行时，只需将=改为IN即可。如果不希望子查询返回多行，则需要修复原始查询

UPDATE users 
SET group_id =
    (
    SELECT Prov_Current_Address_City
    FROM users
    WHERE scope IS NULL
    AND health_facility_id IN
        (
        SELECT Prov_Current_Address_City
        FROM users
        WHERE scope IS NULL
        )
    ) 
WHERE scope IN ('MHO', 'Mayor', 'Doctor')
AND health_facility_id IN
    (
    SELECT health_facility_id
    FROM users
    WHERE scope IS NULL
    );

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请解释你想完成什么。样本数据和期望的结果都会有帮助。问题已更新。更新为或多或少的随机值，而不是更正错误？如何通过随机排序进行选择看这里我尝试了你的答案，但仍然相同result@Claude尝试这种新方法，现在所有仅选择查询只返回1行。，如果这也不起作用，您必须在dbfiddle.uk中构建一个示例数据库，因为我相信您最终可以对结果进行分组。同样的结果不起作用