#31917 closed Uncategorized (invalid)
MySQL Operational Error: "Unknown column 'x' in 'having clause'"
Reported by: | StefanosChaliasos | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | |
Severity: | Normal | Keywords: | |
Cc: | Adam Johnson | Triage Stage: | Unreviewed |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
I have the following model.
class Example(models.Model): id = models.AutoField(primary_key=True,blank=True, null=True) f1 = models.IntegerField(blank=True, null=True) f2 = models.IntegerField(blank=True, null=True) class Meta: managed = False db_table = 'example'
Based on this model, I perform the following query in a MySQL backend.
x = 5 expr = Sum(F('f2')) o = Example.objects.using('mysql') q = o.values('id', 'f1').annotate(expr=expr).order_by('id','expr','-f1',).filter(expr__gt=(F('f1') + Value(x))).values('expr').first()
Unfortunately, this query crashes with an OperationalError exception. The track trace is
Traceback (most recent call last): File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 84, in _execute return self.cursor.execute(sql, params) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/mysql/base.py", line 73, in execute return self.cursor.execute(query, args) File "/home/.env/lib/python3.6/site-packages/MySQLdb/cursors.py", line 206, in execute res = self._query(query) File "/home/.env/lib/python3.6/site-packages/MySQLdb/cursors.py", line 319, in _query db.query(q) File "/home/.env/lib/python3.6/site-packages/MySQLdb/connections.py", line 259, in query _mysql.connection.query(self, query) MySQLdb._exceptions.OperationalError: (1054, "Unknown column 'example.f1' in 'having clause'") The above exception was the direct cause of the following exception: Traceback (most recent call last): File "example.py", line 25, in <module> q = o.values('id', 'f1').annotate(expr=expr).order_by('id','expr','-f1',).filter(expr__gt=(F('f1') + Value(x))).values('expr').first() File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/query.py", line 678, in first for obj in (self if self.ordered else self.order_by('pk'))[:1]: File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/query.py", line 287, in __iter__ self._fetch_all() File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/query.py", line 1316, in _fetch_all self._result_cache = list(self._iterable_class(self)) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/query.py", line 111, in __iter__ for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size): File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/sql/compiler.py", line 1115, in results_iter results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch, chunk_size=chunk_size) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/models/sql/compiler.py", line 1160, in execute_sql cursor.execute(sql, params) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 98, in execute return super().execute(sql, params) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 66, in execute return self._execute_with_wrappers(sql, params, many=False, executor=self._execute) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 75, in _execute_with_wrappers return executor(sql, params, many, context) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 84, in _execute return self.cursor.execute(sql, params) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/utils.py", line 90, in __exit__ raise dj_exc_value.with_traceback(traceback) from exc_value File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/utils.py", line 84, in _execute return self.cursor.execute(sql, params) File "/home/.env/lib/python3.6/site-packages/Django-3.2-py3.6.egg/django/db/backends/mysql/base.py", line 73, in execute return self.cursor.execute(query, args) File "/home/.env/lib/python3.6/site-packages/MySQLdb/cursors.py", line 206, in execute res = self._query(query) File "/home/.env/lib/python3.6/site-packages/MySQLdb/cursors.py", line 319, in _query db.query(q) File "/home/.env/lib/python3.6/site-packages/MySQLdb/connections.py", line 259, in query _mysql.connection.query(self, query) django.db.utils.OperationalError: (1054, "Unknown column 'example.f1' in 'having clause'")
The generated SQL query is
SELECT SUM(`example`.`f2`) AS `expr` FROM `example` GROUP BY `example`.`id`, (`example`.`f1` + %s) HAVING SUM(`example`.`f2`) > (`example`.`f1` + %s) ORDER BY `example`.`id` ASC, `expr` ASC, `example`.`f1` DESC LIMIT 1
Note that although MySQL crashes, this query works as expected in SQLite and Postgres.
Django Version: 3.2
Change History (4)
comment:1 by , 4 years ago
Component: | Uncategorized → Database layer (models, ORM) |
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Resolution: | → invalid |
Status: | new → closed |
comment:2 by , 4 years ago
Hello again,
Base on this MySQL report https://bugs.mysql.com/bug.php?id=100094, Django produces a query that is invalid according to SQL standard.
comment:3 by , 4 years ago
Cc: | added |
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Django produces a query that is invalid according to SQL standard.
I'm sorry but I don't see this. IMO the main issue is that MySQL doesn't recognize that f1
is included in the GROUP BY
clause.
comment:4 by , 4 years ago
I agree, this is a MySQL/MariaDB bug, and there's not much we can do about it. Any workaround we'd introduce would be invalidated if/when either of them fix it, and would be more complex than the user-level workaround of adding the field to the values()
selection.
IMO it's an issue in MySQL not in Django itself, see Bug #78395. Expression is included in the
GROUP BY
clause so it should work properly according to MySQL docs:As a workaround you can add
f1
to the selected columns.values('f1', 'expr')
.