I have this select of MySQL:
SELECT credor.nome, banco.descricao FROM credor
INNER JOIN banco ON (credor.banco = banco.codigo)
It returns me all the lenders and their respective bank, but if the bank of the guy is NULL it just does not return the registry.
How can I do to return the record but in the description get NULL?
What INNER JOIN does is just eliminate NULL s. It only establishes a relationship when there is no NULL on either end.
What you're looking for is done with LEFT JOIN :
SELECT credor.nome, banco.descricao FROM credor
LEFT JOIN banco ON (credor.banco = banco.codigo)
Here on the site you have an excellent explanation of the types of JOIN : What is the difference between INNER JOIN and OUTER JOIN? / a>