carcard.C_Status = 1;
类似这种on后面有多种条件的且需要全部要满足的时候可以用 inner join
这个相当于以下的内容：
SELECT carcard.*, car.Car, car.`user`, Card.Card FROM carcard,car,card where ( carcard.CarId = Car.CarID AND car.Car_Status > 0) and ( carcard.CardId = card.CardID AND card.D_Status > 0 ) and carcard.C_Status = 1;
左连接 left join
会将坐标的数据都返回，注意这个返回是建立在on的基础上即右表如果有多条数据满足左表,则会将左表的记录复制几遍。且on 后面跟and 不会同时筛选，这里的and类似||。
SELECT p.Price, p.SupplierId,p.CreatedTime FROM ProcurementSubs as p where p.LiaoHaoSysId='68f51079-3438-453b-a1fd-155c25d1114b' and p.SupplierId='5fe72c08-183b-4e94-be57-164c2c0f5f9f' ORDER BY p.CreatedTime DESC ; SELECT TOP 1 p.Price, p.SupplierId,p.CreatedTime FROM ProcurementSubs as p where p.LiaoHaoSysId='68f51079-3438-453b-a1fd-155c25d1114b' and p.SupplierId='5fe72c08-183b-4e94-be57-164c2c0f5f9f' ORDER BY p.CreatedTime DESC ; SELECT p.SupplierId FROM ProcurementSubs as p where p.LiaoHaoSysId='68f51079-3438-453b-a1fd-155c25d1114b' GROUP BY p.SupplierId; SELECT p.Price, p.SupplierId,p.CreatedTime from ProcurementSubs as p where p.LiaoHaoSysId='68f51079-3438-453b-a1fd-155c25d1114b' ORDER BY p.CreatedTime DESC; SELECT p.SupplierId ,CHECKSUM_AGG (DISTINCT p.Price) from ProcurementSubs as p where p.LiaoHaoSysId='68f51079-3438-453b-a1fd-155c25d1114b' GROUP BY p.SupplierId ORDER BY MAX(p.CreatedTime);
//sql sever 触发器
DECLARE @t1 decimal DECLARE @t2 decimal DECLARE @Id int //声明变量 select @t1=TaskSubNumber,@t2=TaskSubPlanNumber, @Id = Id from Inserted //给变量赋值 if(@t1=@t2) 条件 BEGIN update SubTasks set SubTasks.Note='触发' where id = @Id;
rollback// 回滚 End
declare @icount int select @icount = COUNT(*) from Drug_Info,Stock where Stock.drug_ID=Drug_Info.drug_ID and Stock.stock_qty<Drug_Info.lower_limit if @icount ..
sql 视图
SELECT ************ FROM dbo.TaskMains ,dbo.OldBoms where dbo.TaskMains.BomSysId=dbo.OldBoms.BomSysId and dbo.OldBoms.VersionId=(SELECT MAX(dbo.OldBoms.VersionId) FROM dbo.OldBoms);
