Unknown SQL Error in PHP [duplicate]

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• Reference - What does this error mean in PHP? 28 answers

When you run this code

mysqli_query($dbc, "insert into toons values(NULL, $toonId, '$toonName', $admin, '$dna', $bank, $money, $hp, '$inventory', $lastPlace)")

I get the error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' '', , '', , , , '', )' at line 1

Does anyone know whats going on? Thanks!