MySQL Insert Statement ONLY IF a duplicate entry does not exist
This is a great way to reduce MySQL code/mistakes/annoyance when doing things, take for example this statement:
INSERT IGNORE INTO sometable(CatName) VALUES("someitem");
Notice the "IGNORE", that is what does the magic.
Normally if the entry "someitem" existed you'd get an error message back such as "Duplicate entry for whatever". What I have normally done in PHP or whatever language is manually coded or made a........
MySQL Error "ERROR 1045 (28000): Access denied for user"
This happened with a select statement which writes the result to an external file. I didn't remember the privilege "FILE" must be granted on *.* for this to work successfully, it wasn't actually an authentication issue as it implies since I was already in the SQL prompt and doing the query.
SELECT some_id
FROM sometable
INTO OUTFILE '/tmp/result.txt'........