SELECT WO_BreakerRail.ID,indRailType.RailType,indRailType.RailCode,WO_BreakerRail.CreatedPieces,WO_BreakerRail.OutsideSource,WO_BreakerRail.Charged,WO_BreakerRail.Rejected,WO_BreakerRail.RejectedToCrop,WO_BreakerRail.DateFROM indRailType LEFT OUTER JOIN WO_BreakerRail ON indRailType.RailCode = WO_BreakerRail.RailCode AND WO_BreakerRail.Date = @date返回时,日期列为NULL没有来自价值WO_BreakerRail的匹配行。有没有办法用@date替换那些NULL值?. o2 v% |0 O0 d' H& z
. j* Y$ w7 P3 z8 `# ^解决方案: ) r$ X; w3 E+ A( m& g3 {3 Z
在oracle和sql server中,可用COALESCE(oracle4 [6 }1 F* k* f. N
version)函数 6 i, Z% [8 |9 N5 j8 ~- y3 USELECT ....,COALESCE(WO_BreakerRail.Date,@date)