错误的写法
SELECT StartDate, ClientID, COUNT(1) AS Total FROM dbo.tbm_cti_CustomTableItem_BudgetPeriod WHERE COUNT(1) <> 1 GROUP BY StartDate, ClientID;
正确的写法
SELECT StartDate, ClientID, COUNT(1) AS Total FROM dbo.tbm_cti_CustomTableItem_BudgetPeriod GROUP BY StartDate, ClientID HAVING COUNT(1) <> 1;
SQL Query aggregate may not appear in WHERE clause
原文：https://www.cnblogs.com/chucklu/p/14338327.html