Is your feature request related to a problem? Please describe.
I'm always frustrated when i do a to and fro in queries and end up adding redundant where's. There could be other such client side text based sanitities which could be implemented with regex checks.

Describe the solution you'd like
the editor simply should barf out if there is already a where clause in the statement. This could be a simple red underline while writing the query itself.

Describe alternatives you've considered
Not preferring it, but we could also just replace all additional where's with and. I don't prefer this because i don't think the editor should decide for the user.

How important is this feature to you?
Not that important but i can help out here with a bit of handholding.

Additional context
Add any other context or screenshots about the feature request here.