Biggest difference between Table variables & Temp tables in Sql Server

BEGIN TRAN

declare @Test_var table

(

id int, data varchar(20)

)

create table #temp_table

(

id int, data varchar(20)

)

insert into @Test_var

select 1, 'data 1' union all

select 2, 'data 2' union all

select 3, 'data 3'

insert into #temp_table

select 1, 'data 1' union all

select 2, 'data 2' union all

select 3, 'data 3'

select * from #temp_table

select * from @Test_var

ROLLBACK

select * from @Test_var

/*

We see that the table variable still exists and has all it's data unlike the temporary table that doesn't exists when the transaction rollbacked.

This little known fact can be very handy in a bunch of different scenarions.