ignore LEFT JOIN when is a empty field, is possible?

[Alexandre Salomé]

Hello!

I am needing a little help in my code:

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SELECT * FROM oficial.tc_devices AS d LEFT JOIN cadastro_veiculo AS f ON d.contact = f.hinova_placa

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How I ignore / "not join" when the d.contact is empty? (because is causing a problem with bad join information? (must NOT join empty field)

I tried search on google, but I could not found the answer.

Thanks in advance

Aecs