我有这个程序
SELECT COUNT( a.id_badania ) AS iloscBadan, COUNT( b.zdjecie ) AS iloscZdjec, COUNT (SELECT id_badania FROM Badania WHERE status='W trakcie realizacji';)
FROM Badania a
INNER JOIN Zdjecia b ON a.id_badania = b.id_badania
还有这个错误
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT id_badania FROM Badania WHERE status='W trakcie realizacji') FROM Badani' at line 1
我不太了解sql。
最佳答案
您可以使用带有 case 语句的 sum 来计算特定状态的值
SELECT COUNT( a.id_badania ) AS iloscBadan, COUNT( b.zdjecie ) AS iloscZdjec, Sum( case when status='W trakcie realizacji' then 1 else 0 end )
FROM Badania a
INNER JOIN Zdjecia b ON a.id_badania = b.id_badania
关于mysql - 错误-选择内部计数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26087130/