README.md edited

.venv/lib/python3.10/site-packages/django/db/backends/mysql/compiler.py

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+from django.core.exceptions import FieldError, FullResultSet
+from django.db.models.expressions import Col
+from django.db.models.sql import compiler
+
+
+class SQLCompiler(compiler.SQLCompiler):
+    def as_subquery_condition(self, alias, columns, compiler):
+        qn = compiler.quote_name_unless_alias
+        qn2 = self.connection.ops.quote_name
+        sql, params = self.as_sql()
+        return (
+            "(%s) IN (%s)"
+            % (
+                ", ".join("%s.%s" % (qn(alias), qn2(column)) for column in columns),
+                sql,
+            ),
+            params,
+        )
+
+
+class SQLInsertCompiler(compiler.SQLInsertCompiler, SQLCompiler):
+    pass
+
+
+class SQLDeleteCompiler(compiler.SQLDeleteCompiler, SQLCompiler):
+    def as_sql(self):
+        # Prefer the non-standard DELETE FROM syntax over the SQL generated by
+        # the SQLDeleteCompiler's default implementation when multiple tables
+        # are involved since MySQL/MariaDB will generate a more efficient query
+        # plan than when using a subquery.
+        where, having, qualify = self.query.where.split_having_qualify(
+            must_group_by=self.query.group_by is not None
+        )
+        if self.single_alias or having or qualify:
+            # DELETE FROM cannot be used when filtering against aggregates or
+            # window functions as it doesn't allow for GROUP BY/HAVING clauses
+            # and the subquery wrapping (necessary to emulate QUALIFY).
+            return super().as_sql()
+        result = [
+            "DELETE %s FROM"
+            % self.quote_name_unless_alias(self.query.get_initial_alias())
+        ]
+        from_sql, params = self.get_from_clause()
+        result.extend(from_sql)
+        try:
+            where_sql, where_params = self.compile(where)
+        except FullResultSet:
+            pass
+        else:
+            result.append("WHERE %s" % where_sql)
+            params.extend(where_params)
+        return " ".join(result), tuple(params)
+
+
+class SQLUpdateCompiler(compiler.SQLUpdateCompiler, SQLCompiler):
+    def as_sql(self):
+        update_query, update_params = super().as_sql()
+        # MySQL and MariaDB support UPDATE ... ORDER BY syntax.
+        if self.query.order_by:
+            order_by_sql = []
+            order_by_params = []
+            db_table = self.query.get_meta().db_table
+            try:
+                for resolved, (sql, params, _) in self.get_order_by():
+                    if (
+                        isinstance(resolved.expression, Col)
+                        and resolved.expression.alias != db_table
+                    ):
+                        # Ignore ordering if it contains joined fields, because
+                        # they cannot be used in the ORDER BY clause.
+                        raise FieldError
+                    order_by_sql.append(sql)
+                    order_by_params.extend(params)
+                update_query += " ORDER BY " + ", ".join(order_by_sql)
+                update_params += tuple(order_by_params)
+            except FieldError:
+                # Ignore ordering if it contains annotations, because they're
+                # removed in .update() and cannot be resolved.
+                pass
+        return update_query, update_params
+
+
+class SQLAggregateCompiler(compiler.SQLAggregateCompiler, SQLCompiler):
+    pass