我正在比较两个表，并希望从表中获取旧表中不存在的新行

Question

select * from New_tr 
where **(PeopleSoftID,** TransDate,TransactionCode)  not in 
(select PeopleSoftID,TransDate,TransactionCode from Old_tr) 

它显示以下错误错误：

An expression of non-boolean type specified in a context where a condition is expected, near ','.

可能导致错误的原因是什么？

Answer 1

我相信根据您使用MS SQL Server的错误消息。 MS SQL Server不支持IN语句中的多个列。您可以轻松地将其重写为左连接，其中where为null以解决您的问题

SELECT * FROM New_tr
LEFT JOIN Old_tr ON (Old_tr.PeopleSoftID = New_tr.PeopleSoftID 
                     and Old_tr.TransDate = New_tr.TransDate 
                     and Old_tr.TransactionCode = New_tr.TransactionCode)
where Old_tr.PeopleSoftID is null