Why are MySQL syntax error messages so bad?

Question

MySQL syntax errors are often pretty vague, only specifying the line where the error occurs. Writing a parser that produces accurate and useful error message is not completely trivial, but it's not an open research problem: most compilers for general purpose programming languages produce errors messages that are much more useful.

So why doesn't MySQL's parser produce better error messages? Is it something to do with MySQL specifically, or the SQL grammar generally that makes this extremely difficult?

Here's an example:

SELECT * FROM foo WHERE bar > 0 AND baz NOT NULL ORDER BY qux ASC 

MySQL generates the following error message: 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 'NULL ORDER BY qux ASC'

In fact, NOT NULL should be IS NOT NULL. So why doesn't MySQL generate an error like Unexpected token NOT at line 3 column 8?

Answer 1

Oracle is where open source software goes to die. They have a disincentive to make the freely available competitor to their commercial database applications very good. It was good enough that no one would make another, for a while, and now I prefer MariaDB and the other forks when I am given a choice.