Question

I have a question regarding my attempt to combine two tables in sql server…

I have one table that has about 30 columns (table a), and a second table that has about 5 (table b), those 5 being present in the 30 column table. I want to be able to add table b to the end of table a, and just use 0 values for the nonexistent columns in the new rows.

Is there a way to do this? Obviously a regular union wouldnt work if I want to keep the other columns in table a.

Answer 1

The basic idea is this, assuming col3 does not exist in TableB:

select col1, col2, col3 from TableA

union all

select col1, col2, 0 as col3 from TableB

Be careful to keep the data types the same within each column.

To keep the TableB records at the end, do:

select col1, col2, col3
from (
    select 1 as Rank, col1, col2, col3 from TableA

    union all

    select 2 as Rank, col1, col2, 0 as col3 from TableB
) a
order by Rank