MySQL：错误代码：1242 子查询 returns 多于 1 行

Question

SELECT daire.code, daire.durumu, daire.blblkodu, CONCAT(cari.adi , cari.soyadi) AS sahibi,
CASE daire.blkrcrkodu WHEN '0'
THEN CONCAT(cari.adi,cari.soyadi)
ELSE (SELECT CONCAT(adi,soyadi)
FROM cari
WHERE blkodu = daire.blkrcrkodu
  AND firma_code = 40
  AND site_code = 84) END AS oturan,
daire.kat, daire.kapi_no, daire.giris_no, daire.alan_m2, daire.__formatted_date
FROM daire
INNER JOIN cari ON
(daire.blshcrkodu = cari.blkodu AND cari.site_code = 84 AND daire.site_code = 84)
WHERE daire.site_code = 84
AND daire.firma_code = 40
ORDER BY daire.blkodu DESC

我有语法错误吗？我不明白是什么问题，你能帮我吗？

Answer 1

如果 subselect return 超过一行但是你需要例如第一个你可以使用 limit 1

SELECT daire.code, daire.durumu, daire.blblkodu, CONCAT(cari.adi , cari.soyadi) AS sahibi,
CASE daire.blkrcrkodu WHEN '0'
THEN CONCAT(cari.adi,cari.soyadi)
ELSE (SELECT CONCAT(adi,soyadi)
        FROM cari
        WHERE blkodu = daire.blkrcrkodu
        AND firma_code = 40
        AND site_code = 84
        LIMIT 1) END AS oturan,
daire.kat, daire.kapi_no, daire.giris_no, daire.alan_m2, daire.__formatted_date
FROM daire
INNER JOIN cari ON
(daire.blshcrkodu = cari.blkodu AND cari.site_code = 84 AND daire.site_code = 84)
WHERE daire.site_code = 84
AND daire.firma_code = 40
ORDER BY daire.blkodu DESC

Answer 2

您在主查询的 select 列表中有一个子查询：

...
(SELECT CONCAT(adi,soyadi)
 FROM cari
 WHERE blkodu = daire.blkrcrkodu
 AND firma_code = 40
 AND site_code = 84) END AS outran

...

此类子查询必须 return 1 行 1 列（单个值）。您的子查询 return 有 1 列，但 return 超过 1 行，因此出现错误。

关于如何修改查询以满足您的需要，我无法为您提供确切的解决方案，因为您没有分享任何关于查询本身的信息，而且您只是询问了错误是什么。一般可以申请

limit 1 子句将行数限制为 1
使用任何聚合函数，例如 min() 将结果集折叠成一行
将您的 where 条件修改为 return 仅一条记录。

MySQL：错误代码：1242 子查询 returns 多于 1 行

MySQL: Error Code: 1242 Subquery returns more than 1 row

mysql

subquery

mysql-error-1242