startswith and contains doesn't work with F expression

[ronnas@…]

The expression:

myTable.objects.filter(field1__startswith=F('field2'))

rendered to:

SELECT * FROM `my_table` WHERE `my_table`.`field1` LIKE `my_table`.`field2`

should be:

SELECT * FROM `my_table` WHERE `my_table`.`field1` LIKE CONCAT(`my_table`.`field2`,'%')

[Aymeric Augustin]

Fixed formatting - please use preview.

I have confirmed the problem as follows:

# todo/models.py

class Todo(models.Model):
    summary = models.CharField(max_length=100, verbose_name=_('summary'))
    details = models.TextField(blank=True, verbose_name=_('details'))

% ./manage.py shell

>>> from todo.models import *>>> from django.db.models import F
>>> Todo.objects.filter(details__startswith=F('summary'))
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "django/db/models/query.py", line 66, in __repr__
    data = list(self[:REPR_OUTPUT_SIZE + 1])
  File "django/db/models/query.py", line 81, in __len__
    self._result_cache.extend(self._iter)
  File "django/db/models/query.py", line 266, in iterator
    for row in compiler.results_iter():
  File "django/db/models/sql/compiler.py", line 699, in results_iter
    for rows in self.execute_sql(MULTI):
  File "django/db/models/sql/compiler.py", line 754, in execute_sql
    cursor.execute(sql, params)
  File "django/db/backends/util.py", line 34, in execute
    return self.cursor.execute(sql, params)
  File "django/db/backends/sqlite3/base.py", line 261, in execute
    return Database.Cursor.execute(self, query, params)
DatabaseError: near "ESCAPE": syntax error
>>> from django.db import connection
>>> connection.queries
[{'time': '0.000', 'sql': u'SELECT "todo_todo"."id", "todo_todo"."summary", "todo_todo"."details" FROM "todo_todo" WHERE "todo_todo"."details" LIKE  ESCAPE \'\\\' "todo_todo"."summary" LIMIT 21'}]