Question

I am trying to use a table as a heap queue. However I am having a little trouble figuring out how to take the text that is generated in the dequeue function and perform a execute on it.

Here is the table storing the queue and the dequeue method.

CREATE TABLE [dbo].[Merge_Queued_Work](Sql_Text varchar(2000) NOT NULL)
GO

create procedure usp_dequeueWork
as
  set nocount on;
  delete top(1) from [Merge_Queued_Work] with (rowlock, readpast)
      output deleted.[Sql_Text];      
go

How do I get the varchar from deleted.[Sql_Text] to a execute statement?

Answer 1

Capture the output in a table variable and fill a varchar variable from the table variable.

create procedure usp_dequeueWork
as
  set nocount on;

  declare @T table(Sql_Text varchar(2000))
  declare @S varchar(2000)

  delete top(1) from [Merge_Queued_Work] with (rowlock, readpast)
      output deleted.[Sql_Text] into @T;      

  select @S = Sql_Text from @T

  exec (@S)