How to combine results of two queries into a single dataset

Here is an example that does a union between two completely unrelated tables: the Student and the Products table. It generates an output that is 4 columns:

select
        FirstName as Column1,
        LastName as Column2,
        email as Column3,
        null as Column4
    from
        Student
union
select
        ProductName as Column1,
        QuantityPerUnit as Column2,
        null as Column3,
        UnitsInStock as Column4
    from
        Products

Obviously you'll tweak this for your own environment...

I think you are after something like this; (Using row_number() with CTE and performing a FULL OUTER JOIN )

Fiddle example

;with t1 as (
  select col1,col2, row_number() over (order by col1) rn
  from table1 
),
t2 as (
  select col3,col4, row_number() over (order by col3) rn
  from table2
)
select col1,col2,col3,col4
from t1 full outer join t2 on t1.rn = t2.rn

Tables and data :

create table table1 (col1 int, col2 int)
create table table2 (col3 int, col4 int)

insert into table1 values
(1,2),(3,4)

insert into table2 values
(10,11),(30,40),(50,60)

Results :

|   COL1 |   COL2 | COL3 | COL4 |
---------------------------------
|      1 |      2 |   10 |   11 |
|      3 |      4 |   30 |   40 |
| (null) | (null) |   50 |   60 |

How about,

select
        col1, 
        col2, 
        null col3, 
        null col4 
    from Table1
union all
select 
        null col1, 
        null col2,
        col4 col3, 
        col5 col4 
    from Table2;

The problem is that unless your tables are related you can't determine how to join them, so you'd have to arbitrarily join them, resulting in a cartesian product:

select Table1.col1, Table1.col2, Table2.col3, Table2.col4
from Table1
cross join Table2

If you had, for example, the following data:

col1  col2
a     1
b     2

col3  col4
y     98
z     99

You would end up with the following:

col1  col2  col3  col4
a     1     y     98
a     1     z     99
b     2     y     98
b     2     z     99

Is this what you're looking for? If not, and you have some means of relating the tables, then you'd need to include that in joining the two tables together, e.g.:

select Table1.col1, Table1.col2, Table2.col3, Table2.col4
from Table1
inner join Table2
on Table1.JoiningField = Table2.JoiningField

That would pull things together for you into however the data is related, giving you your result.

If you mean that both ProductName fields are to have the same value, then:

SELECT a.ProductName,a.NumberofProducts,b.ProductName,b.NumberofProductsSold FROM Table1 a, Table2 b WHERE a.ProductName=b.ProductName;

Or, if you want the ProductName column to be displayed only once,

SELECT a.ProductName,a.NumberofProducts,b.NumberofProductsSold FROM Table1 a, Table2 b WHERE a.ProductName=b.ProductName;

Otherwise,if any row of Table1 can be associated with any row from Table2 (even though I really wonder why anyone'd want to do that), you could give this a look.

How to combine results of two queries into a single dataset

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