I have two tables with the following data (that I did not create nor can I control) that correlate on table1.workgroup = table2.id.

Table1

Table2

I need to find where table1.workgroup does not have a correlating record in table2.

CodePudding user response：

SELECT workgroup
FROM TABLE_1 
  EXCEPT
SELECT id
FROM TABLE_2

CodePudding user response：

Yet another option:

SELECT Table1.workgroup
FROM      Table1
LEFT JOIN Table2 
       ON Table1.workgroup = Table2.id
WHERE Table2.id IS NULL

CodePudding user response：

select * from a.workgroup
from a inner join table2 b on a.workgroup =b.id where table2.id is null