Question

我有一个庞大的SQL语句，升级到MySQL 5.7后，我收到以下错误：

不正确使用union和limit

这是初始查询：

SELECT    tx_wbfincas_domain_model_finca.*,
          helper.*
FROM      tx_wbfincas_domain_model_finca
LEFT JOIN tx_wbfincas_domain_model_finca_searchhelper AS helper
ON        tx_wbfincas_domain_model_finca.uid = helper.finca_uid
WHERE     hidden=0
AND       deleted=0
AND       helper.persons =
          (
                 SELECT IF(Min(shelper.persons) IS NULL, 1000, Min(shelper.persons)) as tb1
                 FROM   tx_wbfincas_domain_model_finca_searchhelper                  AS shelper
                 WHERE  shelper.finca_uid = tx_wbfincas_domain_model_finca.uid limit 1
                 UNION
                          (
                                 SELECT max(shelper.persons)                        AS tb1
                                 FROM   tx_wbfincas_domain_model_finca_searchhelper AS shelper
                                 WHERE  shelper.finca_uid = tx_wbfincas_domain_model_finca.uid limit 1 )
                 ORDER BY tb1 ASC limit 1)
AND       uid IN
          (
                 SELECT uid_local
                 FROM   tx_wbfincas_finca_category_mm
                 WHERE  uid_foreign=4)
GROUP BY  uid
ORDER BY  min_price ASC ;

https://pastebin.com/H2eaNzJ6

我已经尝试插入更多括号，如下所示：

SELECT    tx_wbfincas_domain_model_finca.*,
          helper.*
FROM      tx_wbfincas_domain_model_finca
LEFT JOIN tx_wbfincas_domain_model_finca_searchhelper AS helper
ON        tx_wbfincas_domain_model_finca.uid = helper.finca_uid
WHERE     hidden=0
AND       deleted=0
AND       helper.persons =
          ((SELECT IF(Min(shelper.persons) IS NULL, 1000, Min(shelper.persons)) as tb1
                    FROM   tx_wbfincas_domain_model_finca_searchhelper                  AS shelper
                    WHERE  shelper.finca_uid = tx_wbfincas_domain_model_finca.uid limit 1 )
                 UNION
                 (SELECT max(shelper.persons) as tb1
                         FROM   tx_wbfincas_domain_model_finca_searchhelper AS shelper
                         WHERE  shelper.finca_uid = tx_wbfincas_domain_model_finca.uid limit 1 )
                 ORDER BY tb1 ASC limit 1)
AND       uid IN
          (SELECT uid_local
                 FROM   tx_wbfincas_finca_category_mm
                 WHERE  uid_foreign=4)
GROUP BY  uid
ORDER BY  min_price ASC ;

https://pastebin.com/mctaxTNL

但后来又出现了另一个错误：

您的SQL语法有错误;查看与您的MySQL服务器版本对应的手册，以便在'UNION'附近使用正确的语法

我在这里做错了什么？

Answer 1

如果您使用limit，则子查询周围需要括号。而且，UNION不是SELECT语法的一部分。。。所以你需要SELECT . . . FROM子查询。所以这可能有用：

 helper.persons = (SELECT tbl1
                   FROM ((SELECT IF(Min(shelper.persons) IS NULL, 1000, Min(shelper.persons)) as tb1
                          FROM tx_wbfincas_domain_model_finca_searchhelper shelper
                    WHERE shelper.finca_uid = tx_wbfincas_domain_model_finca.uid 
                          LIMIT 1
                         ) UNION 
                         (SELECT max(shelper.persons)                        AS tb1
                          FROM   tx_wbfincas_domain_model_finca_searchhelper shelper
                          WHERE shelper.finca_uid = tx_wbfincas_domain_model_finca.uid 
                          LIMIT 1
                         )
                        ) x
                 ORDER BY tb1 ASC 
                 LIMIT 1
                )

Answer 2

我有解决方案：我必须在Union之前删除嵌套Query中的第一个限制。

查询：

SELECT tx_wbfincas_domain_model_finca.*, helper.*   
FROM tx_wbfincas_domain_model_finca 
LEFT JOIN tx_wbfincas_domain_model_finca_searchhelper as helper 
ON tx_wbfincas_domain_model_finca.uid = helper.finca_uid 
WHERE hidden=0 
AND deleted=0 
AND helper.persons = 
    ( 
        SELECT IF(MIN(shelper.persons) IS NULL, 1000, MIN(shelper.persons)) AS tb1 
        FROM tx_wbfincas_domain_model_finca_searchhelper AS shelper 
        WHERE shelper.finca_uid = tx_wbfincas_domain_model_finca.uid 
        UNION 
            ( 
                SELECT MAX(shelper.persons) AS tb1 
                FROM tx_wbfincas_domain_model_finca_searchhelper AS shelper 
                WHERE shelper.finca_uid = tx_wbfincas_domain_model_finca.uid LIMIT 1 
            ) 
                ORDER BY tb1 ASC LIMIT 1 
    )

AND uid IN 
       (
           SELECT uid_local 
           FROM tx_wbfincas_finca_category_mm 
           WHERE uid_foreign=4
      ) 
GROUP BY uid 
ORDER BY min_price ASC

Answer 3

是的，我的第二次尝试是用更多括号。使用您的查询我

Unknown column 'tx_wbfincas_domain_model_finca.uid' in 'where clause'

你的第一个选择应该是＆＃34; SELECT tb1＆＃34;而不是tbl1 - 我是对的吗？

我是否应该加入子查询中的tx_wbfincas_domain_model_finca？

不正确使用union和limit

3 个答案: