[Sqlalchemy-tickets] Issue #3694: Incorrect processing of has_key parameter on JSONB columns with custom types (zzzeek/sqlalchemy)

[Arnout v. M. <iss...@bi...>]

New issue 3694: Incorrect processing of has_key parameter on JSONB columns with custom types
https://bitbucket.org/zzzeek/sqlalchemy/issues/3694/incorrect-processing-of-has_key-parameter

Arnout van Meer:

In our codebase we have a custom type based on JSONB and noticed has_key wasn't working. This seems to be due to parameter to has_key getting run through the bind processor which results in unintended quoting of the parameter string.

Repro case, tested with 1.0.12:


```
#!python

from sqlalchemy import create_engine, Column, Table, MetaData, select, types
from sqlalchemy.dialects.postgresql import JSONB


class CustomJSONBType(types.TypeDecorator):
    impl = JSONB


e = create_engine("postgresql://localhost/jsonb_test", echo=True)
c = e.connect()
t = c.begin()

# this works
table = Table('jsonb_test', MetaData(), Column('data', JSONB))
table.create(c)

c.execute(table.insert(), [{"data": {"x": 2}}])

assert c.scalar(select([table]).where(table.c.data.has_key('x')))

# this doesn't work
table = Table('custom_jsonb_test', MetaData(), Column('data', CustomJSONBType))
table.create(c)

c.execute(table.insert(), [{"data": {"x": 2}}])

assert c.scalar(select([table]).where(table.c.data.has_key('x')))
```