Select to List data from another table

Question

I have a system that registers personal data enc_dados_pessoais and another table that stores complementary data enc_dados_complementares.

In the table personal data the user registers only the basic information and by clicking on move forward, goes to complementary data. I need to list only users who have not completed the complementary data.

To primary key table enc_dados_pessoais is IdUsuarios and the foreign key table enc_dados_complementares is IdUsuarios. So I did it this way:

SELECT * FROM enc_dados_principais princ LEFT JOIN enc_dados_complementares
comp ON princ.IdUsuarios <> comp.IdUsuarios;

But it is not returning who did not fill out, only who filled out the complementary data.

I’ve tried to use INNER JOIN, RIGHT JOIN and JOIN, but it didn’t work either.

Answer 1

Based on comment by Mr Marconi, solved the problem using the NOT IN:

select * from enc_dados_principais where IdUsuarios not in 
(SELECT IdUsuarios FROM enc_dados_complementares);