Optional AND in WHERE statement MySQL

I'm trying to figure out how to allow optional AND statements where there is a LEFT OUTER JOIN since the table is optional when viewing records. However, I have a problem where there is开发者_如何学运维 no files, and in the WHERE statement, like this:

SELECT rec.record_id,
       rec.record_name,
       f.file_name,
       f.file_id
FROM
(
    records rec

    LEFT OUTER JOIN files f ON f.record_id = rec.record_id
)
WHERE rec.record_id = 4928 
AND f.file_approved = 1      <-- this is what returns a zero results

When I remove AND f.file_approved = 1 it returns a record, but when I leave it, it returns no record.

If a record contains no file records, it will not return anything. I need it to check it and if there are no files, it should still be able to return the record (without the files).

---

try moving the condition into the join statement, that way it will only join on the lines if they meet the condition

SELECT rec.record_id,
       rec.record_name,
       f.file_name,
       f.file_id
FROM
(
    records rec

    LEFT OUTER JOIN files f ON f.record_id = rec.record_id AND f.file_approved = 1
)
WHERE rec.record_id = 4928;

---

If yu dont want to force the condition, use the OR instead

WHERE 
  rec.record_id = 4928  
OR 
  f.file_approved = 1