django1/django/db/backends/mysql/compiler.py

44 lines
1.6 KiB
Python

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):
if self.connection.features.update_can_self_select or self.single_alias:
return super().as_sql()
# MySQL and MariaDB < 10.3.2 doesn't support deletion with a subquery
# which is what the default implementation of SQLDeleteCompiler uses
# when multiple tables are involved. Use the MySQL/MariaDB specific
# DELETE table FROM table syntax instead to avoid performing the
# operation in two queries.
result = [
'DELETE %s FROM' % self.quote_name_unless_alias(
self.query.get_initial_alias()
)
]
from_sql, from_params = self.get_from_clause()
result.extend(from_sql)
where, params = self.compile(self.query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(from_params) + tuple(params)
class SQLUpdateCompiler(compiler.SQLUpdateCompiler, SQLCompiler):
pass
class SQLAggregateCompiler(compiler.SQLAggregateCompiler, SQLCompiler):
pass