[2.2.x] Fixed #30408 -- Fixed crash when adding check constraints with LIKE operator on Oracle and PostgreSQL.

The LIKE operator wildcard generated for contains, startswith, endswith and
their case-insensitive variant lookups was conflicting with parameter
interpolation on CREATE constraint statement execution.

Ideally we'd delegate parameters interpolation in DDL statements on backends
that support it but that would require backward incompatible changes to the
Index and Constraint SQL generating methods.

Thanks David Sanders for the report.

Backport of a8b3f96f6acfa082f99166e0a1cfb4b0fbc0eace from master

2 files changed, 3 insertions, 1 deletions

diff --git a/django/db/backends/oracle/schema.py b/django/db/backends/oracle/schema.py
index 0664a4ded5..953d2909ea 100644
--- a/django/db/backends/oracle/schema.py
+++ b/django/db/backends/oracle/schema.py
@@ -22,7 +22,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         if isinstance(value, (datetime.date, datetime.time, datetime.datetime)):
             return "'%s'" % value
         elif isinstance(value, str):
-            return "'%s'" % value.replace("\'", "\'\'")
+            return "'%s'" % value.replace("\'", "\'\'").replace('%', '%%')
         elif isinstance(value, (bytes, bytearray, memoryview)):
             return "'%s'" % value.hex()
         elif isinstance(value, bool):
diff --git a/django/db/backends/postgresql/schema.py b/django/db/backends/postgresql/schema.py
index 7d3482399e..994f43cc55 100644
--- a/django/db/backends/postgresql/schema.py
+++ b/django/db/backends/postgresql/schema.py
@@ -22,6 +22,8 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
     sql_delete_procedure = 'DROP FUNCTION %(procedure)s(%(param_types)s)'
 
     def quote_value(self, value):
+        if isinstance(value, str):
+            value = value.replace('%', '%%')
         # getquoted() returns a quoted bytestring of the adapted value.
         return psycopg2.extensions.adapt(value).getquoted().decode()