Question

I want to insert information into a table only if a particular column entry value is less than or equal to another column value in a parent record. Is this possible with SQL, and if so an example would be very much appreciated.

Answer 1

Yes. With the scant information you’ve provided, this is the best I can do:

insert into child_table (col1, col2, col3, etc)
select 'value1', 'value2', 'value3', etc
from parent_table
where parent_id = 'parent_id_value'
and parent_col1 <= 'somevalue'

The select from parent_table will return one row or no rows – resulting in one row or no rows being inserted.