How to convert cycle to table-based query?

Question

I have a table IDTable with one column ID and also I have one table valued function MyProcedure that takes a parameter. This parameter is my column ID. This function returns a table. I need to call this function for every value in column ID. I have such code:

Declare @ResultTable table(
  ClientID nvarchar(50) null,
  [Date] datetime null,
  Item varchar(100) null
)

Declare @IDTable table(
    id int
 )

 declare @counter as int 
 set @counter = isnull( (select max(id) from @IDTable),0) 
 while @counter<>0 
 begin 
    set @ID = (select id from @IDTable where id=@counter)

    insert into @ResultTable
       select ClientID
              [Date],
              Item
       from MyProcedure (@ID)

    delete from @IBTable where id=@counter 
    set @counter=isnull((select max(id) from @IBTable),0) 
 end

I need to remove while cycle and make set-based alternative. How can I do it?

Answer 1

You can use CROSS APPLY:

   insert into @ResultTable
   select   b.ClientID,
            b.[Date],
            b.Item
   from     @IDTable a
   CROSS    APPLY MyProcedure(a.id) b