随笔记忆:
1 if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[DECTOBIN]') and xtype in (N'FN', N'IF', N'TF')) 2 drop function [dbo].[DECTOBIN] 3 GO 4 5 SET QUOTED_IDENTIFIER ON 6 GO 7 SET ANSI_NULLS ON 8 GO 9 10 create FUNCTION dbo.DECTOBIN(@Dec INT, @StrLen INT) 11 RETURNS VARCHAR(31) 12 AS 13 BEGIN 14 DECLARE @BinStr AS VARCHAR(31) 15 DECLARE @Div2 AS INT 16 DECLARE @Mod2 AS INT 17 IF @Dec < 0 18 RETURN 'NULL' 19 SET @Div2 = @Dec / 2 20 SET @Mod2 = @Dec % 2 21 SET @BinStr = '' 22 WHILE @Div2 <> 0 23 BEGIN 24 SET @BinStr = CAST(@Mod2 AS CHAR(1)) + @BinStr 25 SET @Dec = @Dec / 2 26 SET @Div2 = @Dec / 2 27 SET @Mod2 = @Dec % 2 28 29 END; 30 SET @BinStr = CAST(@Mod2 AS CHAR(1)) + @BinStr 31 IF @StrLen > LEN(@BinStr) 32 BEGIN 33 IF @StrLen > 31 34 SET @StrLen = 31 35 36 DECLARE @ZeroStr VARCHAR(31) 37 DECLARE @OffsetLen TINYINT 38 SET @ZeroStr = '' 39 SET @OffsetLen = @StrLen - LEN(@BinStr) 40 41 WHILE @OffsetLen > 0 42 BEGIN 43 SET @ZeroStr = @ZeroStr + '0' 44 SET @OffsetLen = @OffsetLen - 1 45 END 46 47 SET @BinStr = @ZeroStr + @BinStr 48 END 49 RETURN @BinStr 50 51 END 52 53 54 GO 55 SET QUOTED_IDENTIFIER OFF 56 GO 57 SET ANSI_NULLS ON 58 GO
