sql server 生成随机不重复的字符串

use your DB_NAME
GO

/****** Object:  StoredProcedure [dbo].[sp_CreateRandomInviteCode]    Script Date: 2016/1/20 14:41:10 ******/
DROP PROCEDURE [dbo].[sp_CreateRandomInviteCode]
GO

/****** Object:  StoredProcedure [dbo].[sp_CreateRandomInviteCode]    Script Date: 2016/1/20 14:41:10 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO



/*
    
  DECLARE @return_value int,
      @InviteCode nvarchar(max)

  EXEC  @return_value = [dbo].[sp_CreateRandomInviteCode]
      @DigitLength = 5,
      @InviteCode = @InviteCode OUTPUT


  SELECT  @InviteCode as N'@InviteCode'


  --SELECT  '|' + @InviteCode + '|' as N'@InviteCode'

  --SELECT  'Return Value' = @return_value

  --select char(65)
  --select char(90)
  
  --SELECT CHAR(65 + FLOOR(RAND()*26))

  --select  FLOOR(RAND()*5)

*/



CREATE proc [dbo].[sp_CreateRandomInviteCode](  
  @DigitLength INT=NULL,  
  @InviteCode VARCHAR(MAX)  output
)
AS
BEGIN
   DECLARE @INDEX INT    
   DECLARE @SQL NVARCHAR(MAX)
   DECLARE @RowCounts int
   DECLARE @BOOLBIT BIT  
   DECLARE @RandomStr NVARCHAR(MAX)
   DECLARE @RandomNum int

   DECLARE @randomLetter varchar(1)
   DECLARE @randomLetterPosition INT

   SET @BOOLBIT=1
   SET @RandomStr=''
   SET @INDEX=0

   IF(@DigitLength IS NULL OR @DigitLength<=0)
    SET @DigitLength=1

    --SELECT @randomLetter= CHAR(65 + FLOOR(RAND()*26))
    SELECT @randomLetterPosition=0
  -- SELECT @randomLetterPosition= FLOOR(RAND()* @DigitLength )
 
   WHILE @BOOLBIT=1
   BEGIN
     WHILE @INDEX<@DigitLength
       BEGIN              
        SET @RandomStr=@RandomStr+CONVERT(nvarchar, FLOOR(RAND()*10))    
        SET @INDEX=(@INDEX+1)
       END
 
    SELECT @randomLetter= CHAR(65 + FLOOR(RAND()*26))

    IF(@randomLetter='O' OR @randomLetter='I')
    BEGIN
       --PRINT 'CONTINUE'
        CONTINUE
    END
      
    SET @InviteCode=@randomLetter + @RandomStr   

     --IF(@randomLetterPosition=0)
       --SET @InviteCode=@randomLetter + @RandomStr   
     --ELSE
       --SET @InviteCode=SUBSTRING(@RandomStr,1,@randomLetterPosition) 
        --+ @randomLetter + SUBSTRING(@RandomStr,@randomLetterPosition,@DigitLength - @randomLetterPosition)
 
     IF(EXISTS(SELECT * FROM DoctorInviteCode WHERE InviteCode=@RandomStr))
       BEGIN
          SET @INDEX=0  
        SET @RandomStr=''       
       END
     ELSE
       BEGIN
           SET @BOOLBIT=0         
       END
   
   END    

END


GO

运行结果：

（结束）