简单连接 sql 不明确的列

Question

我遇到了不明确的列错误？尽管它们与我选择的所有其他列完全相同。

SELECT DISTINCT [date], [problem], [companyprofit], [fixtime]
FROM [fixandresponse]  , [netprofit] 
WHERE [fixandresponse].[date] = [netprofit].[date]

Answer 1

因为两个table有相同的列名：date.

你可以试试这个：

SELECT DISTINCT [fixandresponse].[date], [problem], [companyprofit], [fixtime]
FROM [fixandresponse]  , [netprofit] 
WHERE [fixandresponse].[date] = [netprofit].[date]

此外，您应该使用：

SELECT DISTINCT F.[date], F...., N.... -- get column from two table
FROM [fixandresponse] F
  INNER JOIN [netprofit] N
    ON F.[date] = N.[date]

Answer 2

这样测试

Select distinct f.date, f.problem, f.companyprofit, f.fixtime    
from fixandresponse f, netprofit n    
Where f.date = n.date

简单连接 sql 不明确的列

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