Traverse a MSSQL table without using CURSOR

Abdul Quader Mamun

5.00/5 (1 vote)

3 Aug 2012CPOL

13.1K

To traverse a table without cursor, you only need to add an additional field in the table with null value. Here is the code for traversing a table.

Table structure here. In my case Flag is the additional field which contains null value.

CREATE TABLE [dbo].[A](
	[Id] [int] IDENTITY(1,1) NOT NULL PRIMARY KEY,
	[Value] [int] NOT NULL,
	[Flag] [bit] NULL
)

Here is the code for traversing

SQL

BEGIN TRY	

	BEGIN TRANSACTION

	DECLARE @Id int	
		
	WHILE  EXISTS(SELECT TOP 1 * FROM A WHERE Flag IS null)
		BEGIN	
		     --code here
			
		     SELECT TOP 1 @Id=ID FROM A WHERE Flag IS null	
		     UPDATE A WITH (TABLOCK) SET Flag=1 WHERE Id=@Id
		END

	UPDATE A  WITH (TABLOCK) SET Flag=null	
	COMMIT TRANSACTION	
	
END TRY
BEGIN CATCH

	ROLLBACK TRANSACTION
	RAISERROR ('Error, Please try again.',16,1)
		
END CATCH

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)