[Sqlalchemy-tickets] Issue #4254: No way to combine case-insensitive contains() with autoescape (zzzeek/sqlalchemy)

[vr2262 <iss...@bi...>]

New issue 4254: No way to combine case-insensitive contains() with autoescape
https://bitbucket.org/zzzeek/sqlalchemy/issues/4254/no-way-to-combine-case-insensitive

vr2262:

I would like to filter a query with `ILIKE` while escaping special characters like `%` and `_`. I tried this:

```
#!python
from sqlalchemy import *
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()


class Example(Base):
    __tablename__ = 'example'
    id = Column(Integer, primary_key=True)
    string_col = Column(String)


session = sessionmaker()()
session.add(Example(string_col='S%mething'))

search_string = 's%'
print(
    session.query(Example)
    .filter(
        func.lower(Example.string_col)
        .contains(func.lower(search_string), autoescape=True)
    )
)
```
But I get the error `TypeError: String value expected when autoescape=True` because `contains()` expects an actual string as the first argument.

Ideally SQLAlchemy would provide this feature out of the box, perhaps with `icontains()` or `contains(insensitive=True, ...)`.