Fixed #30271 -- Added the Sign database function.

3 files changed, 8 insertions, 2 deletions

diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 7552956cd9..6a19236c48 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -231,6 +231,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         conn.create_function('SHA256', 1, none_guard(lambda x: hashlib.sha256(x.encode()).hexdigest()))
         conn.create_function('SHA384', 1, none_guard(lambda x: hashlib.sha384(x.encode()).hexdigest()))
         conn.create_function('SHA512', 1, none_guard(lambda x: hashlib.sha512(x.encode()).hexdigest()))
+        conn.create_function('SIGN', 1, none_guard(lambda x: (x > 0) - (x < 0)))
         conn.create_function('SIN', 1, none_guard(math.sin))
         conn.create_function('SQRT', 1, none_guard(math.sqrt))
         conn.create_function('TAN', 1, none_guard(math.tan))
diff --git a/django/db/models/functions/__init__.py b/django/db/models/functions/__init__.py
index fb899127d2..c928873661 100644
--- a/django/db/models/functions/__init__.py
+++ b/django/db/models/functions/__init__.py
@@ -7,7 +7,7 @@ from .datetime import (
 )
 from .math import (
     Abs, ACos, ASin, ATan, ATan2, Ceil, Cos, Cot, Degrees, Exp, Floor, Ln, Log,
-    Mod, Pi, Power, Radians, Round, Sin, Sqrt, Tan,
+    Mod, Pi, Power, Radians, Round, Sign, Sin, Sqrt, Tan,
 )
 from .text import (
     MD5, SHA1, SHA224, SHA256, SHA384, SHA512, Chr, Concat, ConcatPair, Left,
@@ -32,7 +32,7 @@ __all__ = [
     # math
     'Abs', 'ACos', 'ASin', 'ATan', 'ATan2', 'Ceil', 'Cos', 'Cot', 'Degrees',
     'Exp', 'Floor', 'Ln', 'Log', 'Mod', 'Pi', 'Power', 'Radians', 'Round',
-    'Sin', 'Sqrt', 'Tan',
+    'Sign', 'Sin', 'Sqrt', 'Tan',
     # text
     'MD5', 'SHA1', 'SHA224', 'SHA256', 'SHA384', 'SHA512', 'Chr', 'Concat',
     'ConcatPair', 'Left', 'Length', 'Lower', 'LPad', 'LTrim', 'Ord', 'Repeat',
diff --git a/django/db/models/functions/math.py b/django/db/models/functions/math.py
index 1a574eb9ab..909a3088bb 100644
--- a/django/db/models/functions/math.py
+++ b/django/db/models/functions/math.py
@@ -146,6 +146,11 @@ class Round(Transform):
     lookup_name = 'round'
 
 
+class Sign(Transform):
+    function = 'SIGN'
+    lookup_name = 'sign'
+
+
 class Sin(NumericOutputFieldMixin, Transform):
     function = 'SIN'
     lookup_name = 'sin'