Introduction
Let's say we have a simple table of lookup values and that we want to get a list of these values into a simple comma delimited character list. We can accomplish this with either a traditional CURSOR or a WHILE loop. However, listed below is an easier way to produce the same list without having to use the infamous CURSOR.
Method
To illustrate this new approach, let's create a small table called MyStatus and load it with some sample entries.
CREATE TABLE [dbo].[MyStatus]( [Status_Id] [int] IDENTITY(1,1) PRIMARY KEY NOT NULL, [StatusDesc] [varchar](25) NULL, )
Now let's load this table with some sample values using INSERT statements.
INSERT INTO MyStatus VALUES ('Active') INSERT INTO MyStatus VALUES ('OnHold') INSERT INTO MyStatus VALUES ('Disabled') INSERT INTO MyStatus VALUES ('Closed')
Now our objective is to create a list of comma delimited valid values, for example: Active,OnHold,Disabled,Closed
To get this list one would normally use a CURSOR (or a WHILE loop) as listed below:
/*--------------- CURSOR approach --------------- */DECLARE @MyStatusList VARCHAR(1000) DECLARE @StatusDesc VARCHAR(25) DECLARE myCursor CURSOR FOR SELECT StatusDesc FROM MyStatus OPEN myCursor SET @MyStatusList = '' FETCH NEXT FROM myCursor INTO @StatusDesc WHILE @@FETCH_STATUS = 0 BEGIN SET @MyStatusList = ISNULL(@MyStatusList,'') + @StatusDesc + ',' FETCH NEXT FROM myCursor INTO @StatusDesc END CLOSE myCursor DEALLOCATE myCursor /* drop the trailing delimiter and display */SET @MyStatusList = SUBSTRING(@MyStatusList, 1, LEN(@MyStatusList)-1) SELECT @MyStatusList /*--------------- End of CURSOR approach --------------- */
Now, here is a simpler technique to get the same result without having to use a CURSOR (or a WHILE loop)
SET @MyStatusList = '' SELECT @MyStatusList = ISNULL(@MyStatusList,'') + StatusDesc + ',' FROM MyStatus
If only distinct values are needed, then one must replace the above SELECT statement with the one below.
SELECT @MyStatusList = ISNULL(@MyStatusList,'') + StatusDesc + ',' FROM (SELECT DISTINCT StatusDesc FROM MyStatus) x
Finally drop the trailing comma at the end and then display.
SET @MyStatusList = SUBSTRING(@MyStatusList, 1, LEN(@MyStatusList)-1) SELECT @MyStatusList
Conclusion
In this article, we provided a simple way to get a comma delimited list from a table of entries without having to use a CURSOR or a WHILE loop to read through the table. We also listed the actual T-SQL code to accomplish this task, along with an example table and some sample entries.