Please start any new threads on our new site at http://forums.sqlteam.com. We've got lots of great SQL Server experts to answer whatever question you can come up with.

Our new SQL Server Forums are live! Come on over! We've restricted the ability to create new threads on these forums.

SQL Server Forums
Profile | Active Topics | Members | Search | Forum FAQ
 
Register Now and get your question answered!
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 SQL Server 2012 Forums
 Transact-SQL (2012)
 Looping until condition met in sp
 Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

GregDDDD
Posting Yak Master

120 Posts

Posted - 02/25/2014 :  12:31:24  Show Profile  Reply with Quote
I've never written a loop in an sp and I'm concerned with run away code. The idea is to create a unique value based on a root value, parameters passed in, and then a random number. Compare that to a column in the database to see if it already exists, and if it doesn't return that value. If it does exist try again with a new random number, look up, etc.

Does this look like good logic below? @County and @Type are passed in as parameters.

Greg



	DECLARE @ROOT_OID VARCHAR(22)
	SET @ROOT_OID = '2.16.840.1.113883.17.7'

	DECLARE @MPIOut VARCHAR(50)
	DECLARE @MPILookUp VARCHAR(50)
	
	DECLARE @Stop int
	DECLARE @Lower int
	DECLARE @Upper int
	DECLARE @Random int
	SET @Lower = 1     -- The lowest random number
	SET @Upper = 99999 -- The highest random number

	SET @Stop = 0

	WHILE (@Stop=0) BEGIN

		SELECT @Random = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)	

		DECLARE @CountyCode VARCHAR(2)
		SELECT @CountyCode = CASE WHEN @County = 1 THEN '.1' WHEN @County = 2 THEN '.2' ELSE '.0' END
	
		DECLARE @TypeCode VARCHAR(2)
		SELECT @TypeCode = CASE WHEN @Type = 1 THEN '.1' WHEN @Type = 2 THEN '.2' ELSE '.0' END

		SELECT @MPIOut = @ROOT_OID + @CountyCode + @TypeCode + '.' + CAST(@Random AS VARCHAR)
		--Look up the generated value to see it if has been used
		SELECT @MPILookUp = [item_text] FROM [AICU].[dbo].[tbl_text]  WHERE [item_id] = 11254 AND [item_text] = @MPIOut
                --Set the control variable. If it  = 1 then exit loop
		SELECT @Stop = CASE WHEN @MPILookUp = '' THEN  1   WHEN @MPILookUp IS NULL THEN  1 ELSE 0 END
   
	END

	SELECT @MPIOut

Edited by - GregDDDD on 02/25/2014 12:56:59

GregDDDD
Posting Yak Master

120 Posts

Posted - 02/25/2014 :  12:32:56  Show Profile  Reply with Quote
Just a thought. @MPILookup could be NULL instead of an empty string ''

Greg
Go to Top of Page

jeffw8713
Aged Yak Warrior

USA
819 Posts

Posted - 02/27/2014 :  14:52:20  Show Profile  Reply with Quote
If I am reading this correctly, then it really is not random - as it can be any value between 1 and 99999 at the end. This can be done without a loop - but I don't have the time to put together the code.

Basically, what I would do is build a table of all possible values using a Tally/Numbers table. Then you can outer join that table to your tbl_text table on the item_text column and filter for null values. This will give you a list of all available numbers and from that you can then randomly select one of the values and return it.

If you really have to use a loop, then I would move the @CountyCode and @TypeCode declarations outside the loop and change the logic to use an EXISTS statement where you reset @MPIOut to null if there is a match:

SET @MPIOut = {build up the MPIOut variable};

IF EXISTS (Select * From aicu.dbo.tbl_text Where item_id = 11254 And item_text = @MPIOut)
BEGIN
SET @MPIOut = NULL;
END

Change the WHILE loop to

WHILE (@MPIOut IS NULL)

Once you have a valid value, the loop will stop and return that value.
Go to Top of Page
  Previous Topic Topic Next Topic  
 Reply to Topic
 Printer Friendly
Jump To:
SQL Server Forums © 2000-2009 SQLTeam Publishing, LLC Go To Top Of Page
This page was generated in 0.03 seconds. Powered By: Snitz Forums 2000