Refs #28643 -- Added Repeat database function.

Thanks Tim Graham and Nick Pope for reviews.

3 files changed, 20 insertions, 4 deletions

diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 3989028930..b644f4d42a 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -4,6 +4,7 @@ SQLite3 backend for the sqlite3 module in the standard library.
 import datetime
 import decimal
 import math
+import operator
 import re
 import warnings
 from sqlite3 import dbapi2 as Database
@@ -170,6 +171,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         conn.create_function("django_format_dtdelta", 3, _sqlite_format_dtdelta)
         conn.create_function("django_power", 2, _sqlite_power)
         conn.create_function('LPAD', 3, _sqlite_lpad)
+        conn.create_function('REPEAT', 2, operator.mul)
         conn.create_function('RPAD', 3, _sqlite_rpad)
         conn.execute('PRAGMA foreign_keys = ON')
         return conn
diff --git a/django/db/models/functions/__init__.py b/django/db/models/functions/__init__.py
index a0f5a9e8b2..7515cc67d9 100644
--- a/django/db/models/functions/__init__.py
+++ b/django/db/models/functions/__init__.py
@@ -6,8 +6,8 @@ from .datetime import (
     TruncQuarter, TruncSecond, TruncTime, TruncWeek, TruncYear,
 )
 from .text import (
-    Chr, Concat, ConcatPair, Left, Length, Lower, LPad, LTrim, Ord, Replace,
-    Right, RPad, RTrim, StrIndex, Substr, Trim, Upper,
+    Chr, Concat, ConcatPair, Left, Length, Lower, LPad, LTrim, Ord, Repeat,
+    Replace, Right, RPad, RTrim, StrIndex, Substr, Trim, Upper,
 )
 from .window import (
     CumeDist, DenseRank, FirstValue, Lag, LastValue, Lead, NthValue, Ntile,
@@ -25,8 +25,8 @@ __all__ = [
     'TruncWeek', 'TruncYear',
     # text
     'Chr', 'Concat', 'ConcatPair', 'Left', 'Length', 'Lower', 'LPad', 'LTrim',
-    'Ord', 'Replace', 'Right', 'RPad', 'RTrim', 'StrIndex', 'Substr', 'Trim',
-    'Upper',
+    'Ord', 'Repeat', 'Replace', 'Right', 'RPad', 'RTrim', 'StrIndex', 'Substr',
+    'Trim', 'Upper',
     # window
     'CumeDist', 'DenseRank', 'FirstValue', 'Lag', 'LastValue', 'Lead',
     'NthValue', 'Ntile', 'PercentRank', 'Rank', 'RowNumber',
diff --git a/django/db/models/functions/text.py b/django/db/models/functions/text.py
index aecf64e28e..1f04842153 100644
--- a/django/db/models/functions/text.py
+++ b/django/db/models/functions/text.py
@@ -152,6 +152,20 @@ class Ord(Transform):
         return super().as_sql(compiler, connection, function='UNICODE', **extra_context)
 
 
+class Repeat(BytesToCharFieldConversionMixin, Func):
+    function = 'REPEAT'
+
+    def __init__(self, expression, number, **extra):
+        if not hasattr(number, 'resolve_expression') and number < 0:
+            raise ValueError("'number' must be greater or equal to 0.")
+        super().__init__(expression, number, **extra)
+
+    def as_oracle(self, compiler, connection, **extra_context):
+        expression, number = self.source_expressions
+        rpad = RPad(expression, Length(expression) * number, expression)
+        return rpad.as_sql(compiler, connection, **extra_context)
+
+
 class Replace(Func):
     function = 'REPLACE'