Support all MySQL logical operators

[fulghum]

We currently have support for some, but not all of MySQL's logical operators.

For example, select 1 OR 1; works, but not select 1 XOR 1;. We should review MySQL's logical operators and ensure we support all of them.

Found by: go-sqlsmith

[fulghum]

Now that we've got xor support, it looks like the only other logical operator go-mysql-server doesn't support yet is !.

[joel-rieke]

What about ABS, REGEXP and CONVERT? I think REGEXP and CONVERT are covered but I'm not sure? But ABS I'm pretty sure is not covered.

[timsehn]

Those aren't logical operators. Those are functions. A good list of supported/unsupported functions are in Dolt, the main implementor of go-mysql-server.

https://docs.dolthub.com/sql-reference/sql-language-support/expressions-functions-operators

ABS - Supported
REGEXP - Supported
CONVERT - Not Supported.

Feel free to make a new issue for CONVERT.

[joel-rieke]

What's weird is that the query seems to work fine with CONVERT even... Hm.. but adding ABS it doesn't work. I am stringing together an ABS, a REGEXP, and a CONVERT in a WHERE clause of a JOIN query. Impressed with how close it gets. But agree this doesn't belong under this issue. I have opened another issue to address: dolthub/go-mysql-server#1050

[timsehn]

Looks like CONVERT is supported but maybe only partially.

https://github.com/dolthub/go-mysql-server/blob/main/sql/expression/convert.go

Feel free to make an issue for the query you want to work. I'll update the Dolt docs.

[timsehn]

PR to fix this in docs. I need a second set of eyes on it.

dolthub/docs#638

[timsehn]

Resolving because we added a note on CONVERT()