Question

是否有更好的方法从这个sql proc

获取每日序列＃

  DECLARE @id int

 UPDATE daily_identity 
 SET id = id + 1, @id = id + 1     
 WHERE day = CONVERT(VARCHAR(8), GETDATE(), 112) 
 IF @@ROWCOUNT = 0
     INSERT INTO daily_identity values ( CONVERT(VARCHAR(8), GETDATE(), 112), 1 )
     SELECT @id = 1
 END IF

 SELECT @id AS ‘id’

Answer 1

看起来像一场事故正在等待，而没有非常严格的交易缠绕在它周围。

编辑：强调Row_Number()计算取决于对所有行进行编号。

如何始终执行INSERT并使用结果生成显示的每日ID？你有没有看到有用的东西：

-- Create some sample data.
declare @Today as Date = GetDate()
declare @Stuff as Table ( Id Int Identity, DateAdded Date )
insert into @Stuff ( DateAdded ) values
    ( DateAdd( day, -3, @Today ) ),
    ( DateAdd( day, -2, @Today ) ), ( DateAdd( day, -2, @Today ) ), 
    ( DateAdd( day, -1, @Today ) ), ( DateAdd( day, -1, @Today ) ),
    ( @Today ), ( @Today )

-- Display the test data.
select Id, DateAdded,
    Id - ( select Min( Id ) from @Stuff where DateAdded = S.DateAdded ) as DailyId,
    Row_Number() over ( partition by DateAdded order by Id ) as AlternativeDailyId,
    Convert( VarChar(8), DateAdded, 112 ) + '-' +
        Right( '000000' + Cast( Id - ( select Min( Id ) from @Stuff where DateAdded = S.DateAdded ) as VarChar(10) ), 6 ) as DateId
    from @Stuff as S

-- Add a row.
declare @NewRows as Table ( Id Int, DateAdded Date )
insert into @Stuff
    ( DateAdded )
    output inserted.Id, inserted.DateAdded into @NewRows
    values ( GetDate() )
-- Display the new Id.
--   Note the the   Row_Number()   calculation only works when all rows are counted.
select N.Id, N.DateAdded,
    N.Id - ( select Min( Id ) from @Stuff where DateAdded = N.DateAdded ) as DailyId, -- NB: References @Stuff.     
    Row_Number() over ( partition by N.DateAdded order by N.Id ) as AlternativeDailyId,
    Convert( VarChar(8), N.DateAdded, 112 ) + '-' +
        Right( '000000' + Cast( Id - ( select Min( Id ) from @Stuff where DateAdded = N.DateAdded ) as VarChar(10) ), 6 ) as DateId
    from @NewRows as N
select *
    from (
        select S.Id, S.DateAdded,
            S.Id - ( select Min( Id ) from @Stuff where DateAdded = S.DateAdded ) as DailyId, -- NB: References @Stuff.     
            Row_Number() over ( partition by S.DateAdded order by S.Id ) as AlternativeDailyId,
            Convert( VarChar(8), S.DateAdded, 112 ) + '-' +
                Right( '000000' + Cast( Id - ( select Min( Id ) from @Stuff where DateAdded = S.DateAdded ) as VarChar(10) ), 6 ) as DateId
            from @Stuff as S
        ) as X
    where Id in ( select Id from @NewRows )

请注意，删除行会发生可怕的事情。每日的ID会以惊心动魄的方式重新计算。

在SQL Server中生成每日序列/标识

1 个答案: