Fixed #26140 -- Suppressed MySQL warning when inserting binary content

Thanks Tim Graham for the review.

django/db/backends/base/operations.py

@@ -578,6 +578,13 @@ def combine_expression(self, connector, sub_expressions):
     def combine_duration_expression(self, connector, sub_expressions):
         return self.combine_expression(connector, sub_expressions)
 
+    def binary_placeholder_sql(self, value):
+        """
+        Some backends require special syntax to insert binary content (MySQL
+        for example uses '_binary %s').
+        """
+        return '%s'
+
     def modify_insert_params(self, placeholder, params):
         """Allow modification of insert parameters. Needed for Oracle Spatial
         backend due to #10888.

django/db/backends/mysql/operations.py

@@ -212,6 +212,9 @@ def convert_uuidfield_value(self, value, expression, connection, context):
             value = uuid.UUID(value)
         return value
 
+    def binary_placeholder_sql(self, value):
+        return '_binary %s' if value is not None else '%s'
+
     def subtract_temporals(self, internal_type, lhs, rhs):
         lhs_sql, lhs_params = lhs
         rhs_sql, rhs_params = rhs

django/db/models/fields/__init__.py

@@ -2371,6 +2371,9 @@ def deconstruct(self):
     def get_internal_type(self):
         return "BinaryField"
 
+    def get_placeholder(self, value, compiler, connection):
+        return connection.ops.binary_placeholder_sql(value)
+
     def get_default(self):
         if self.has_default() and not callable(self.default):
             return self.default