sql - How to show only rows where there is no match between strings at all?

Question

I have to compare two columns and be able to extract only rows where there is not even a partial match between strings. For example, I have this table:

Col1	Col2
John Smith	John Smith ltd
Pepper Row	Whatever Pepper
red	Blue

Answer 1

If you want rows where none of the words overlap, you can use a not exists clause:

select t.*
from t
where not exists (select 1
                  from string_split(t.col1, ' ') s1 join
                       string_split(t.col2, ' ') s2
                       on s1.value = s2.value
                 );

Note: This formulation allows you to return the entire row -- that is, other columns that are not included in the comparison.

If you are using an older version of SQL Server that does not support string_split(), I would suggest finding the code for a user-defined function that does the same thing.