SELECT SUM(ISNULL(SL,0)) AS SL FROM (
SELECT SUM(实际值) [SL] FROM TABLE WHERE 日期>=CONCAT(YEAR(GETDATE()),'-01-01') AND 日期<DATEADD(MONTH,((DATEPART(MONTH,GETDATE())/3)*3),CONCAT(YEAR(GETDATE()),'-01-01') )
UNION ALL
SELECT SUM(目标值) [SL] FROM TABLE WHERE 日期>=DATEADD(MONTH,((DATEPART(MONTH,GETDATE())/3)*3),CONCAT(YEAR(GETDATE()),'-01-01') ) AND 日期<=CONCAT(YEAR(GETDATE()),'-12-31')
) T