Cannot Un-escape LIKE wildcards without .extra()

[Doug Dresser]

Currently, django escapes wildcards used in SQL LIKE clauses. See here ​https://docs.djangoproject.com/en/dev/topics/db/queries/#escaping-percent-signs-and-underscores-in-like-statements.

At times, I have found it desirable to actually want wildcards, and there are only two options to replicate this to my knowledge:

1) Raw SQL using .extra()
2) Using a regular expression such as .filter(somefield__regex=<regex_lookup>)

The first option is undesirable because its using raw sql, not high level python. The second is undesirable because SQL REGEX is much much slower than using a LIKE clause with wildcards.

I propose adding an optional parameter (thus allowing backwards compatibility) within .filter(), such as .filter(somefield__contains=FO%BAR, escape=False) which will allow the filter expression to not escape the underscores and percentage signs.

[Simon Charette]

Hello there,

Unfortunately the API you are suggesting through filter(escape=True) is backward incompatible. I'm also not convinced this use case is common enough to warrant the inclusion of such option given this can easily be implemented by registering ​a custom lookup.

e.g.

from django.db import models

class Like(models.Lookup):
    lookup_name = 'like'

    def as_sql(self, compiler, connection):
        lhs, lhs_params = self.process_lhs(compiler, connection)
        rhs, rhs_params = self.process_rhs(compiler, connection)
        params = lhs_params + rhs_params
        return '%s LIKE %s' % (lhs, rhs), params

models.CharField.register_lookup(Like)
models.TextField.register_lookup(Like)

Foo.objects.filter(bar__like='unescaped % or _')