PostgreSQL JSON field filter support

[Glitch-is]

I've been trying to use the given filters on JSON database fields in PostgreSQL but I keep getting the error

HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts

But there is no obvious way to do any type of type casting. All I would like to do is to check if a JSON field contains a string.

Am I just doing something wrong or have JSON fields not been implemented?

[drmclean]

Looks like JSON Filtering is unsupported. Please can we have support for filtering JSON fields?