Can I loop through a table variable in T-SQL?

Question

Is there anyway to loop through a table variable in T-SQL?

DECLARE @table1 TABLE ( col1 int )  
INSERT into @table1 SELECT col1 FROM table2

Answer 1

look like this demo:

DECLARE @vTable TABLE (IdRow int not null primary key identity(1,1),ValueRow int);

-------Initialize---------
insert into @vTable select 345;
insert into @vTable select 795;
insert into @vTable select 565;
---------------------------

DECLARE @cnt int = 1;
DECLARE @max int = (SELECT MAX(IdRow) FROM @vTable);

WHILE @cnt <= @max
BEGIN
    DECLARE @tempValueRow int = (Select ValueRow FROM @vTable WHERE IdRow = @cnt);

    ---work demo----
    print '@tempValueRow:' + convert(varchar(10),@tempValueRow);
    print '@cnt:' + convert(varchar(10),@cnt);
    print'';
    --------------

    set @cnt = @cnt+1;
END

Version without idRow, using ROW_NUMBER

    DECLARE @vTable TABLE (ValueRow int);
-------Initialize---------
insert into @vTable select 345;
insert into @vTable select 795;
insert into @vTable select 565;
---------------------------

DECLARE @cnt int = 1;
DECLARE @max int = (select count(*) from @vTable);

WHILE @cnt <= @max
BEGIN
    DECLARE @tempValueRow int = (
        select ValueRow 
        from (select ValueRow
            , ROW_NUMBER() OVER(ORDER BY (select 1)) as RowId 
            from @vTable
        ) T1 
    where t1.RowId = @cnt
    );

    ---work demo----
    print '@tempValueRow:' + convert(varchar(10),@tempValueRow);
    print '@cnt:' + convert(varchar(10),@cnt);
    print'';
    --------------

    set @cnt = @cnt+1;
END