Compare nulll value with non null value SQL

Question

I have two columns as below:

Column A	Column B
A1	NULL
A1	A1
B1	C1.

When I query these columns as below:

SELECT Column A, Column B
from table
where Column A != Column B

I am expecting the following result:

Column A	Column B
A1	NULL
B1.	C1

But my query is only giving me the second line of the expected result.

Answer 1

Consider below

select *
from your_table
where columnA is distinct from columnB    

with output