Question

sql左连接怎么加条件、、、

public DataSet GetUserBorrowBackBook1(string tbName)
{

return (data.RunProcReturn("select record.*,carinformation.brand,memberinformation.name as name from record " +
" left join carinformation on record.carid=carinformation.carid " +
" left join memberinformation on record.id=memberinformation.id", tbName));
}
左连接没错可以显示 我想选择record表里的id = Session["id"].ToString() 请问要怎么改？

Answer 1

应该加在语句的最后面，作为全局条件，他是指向整条语句的，先连接再计算条件，有个优先级的。
语句写法为：
Select [列1],[列2] from A left Join B on A.[列1]=B.[列5] where A.[列2]<>'张三';

Answer 2

public DataSet GetUserBorrowBackBook1(string tbName) { return (data.RunProcReturn("select record.*,carinformation.brand,memberinformation.name as name from record " + " left join carinformation on record.carid=carinformation.carid " + " left join memberinformation on record.id=memberinformation.id " +
" where record.id='"+ Session["id"].ToString()+"'", tbName)); }

追问

为什么老是出现这个、、、、

追答

你根据你的程序情况调整一下就可以，估计你的是web程序，用request取session

Answer 3

public DataSet GetUserBorrowBackBook1(string tbName) { return (data.RunProcReturn("select record.*,carinformation.brand,memberinformation.name as name from record " + " left join carinformation on record.carid=carinformation.carid " + " left join memberinformation on record.id=memberinformation.id
where record.id = Session["id"].ToString()
", tbName));

}

Answer 4

在最后面加个where子句就可以