55 lines
1.9 KiB
Python
55 lines
1.9 KiB
Python
|
from django.db.models.sql.query import Query
|
||
|
|
|
||
|
|
__all__ = ['CheckConstraint']
|
||
|
|
|
||
|
|
|
||
|
|
class CheckConstraint:
|
||
|
|
def __init__(self, constraint, name):
|
||
|
|
self.constraint = constraint
|
||
|
|
self.name = name
|
||
|
|
|
||
|
|
def constraint_sql(self, model, schema_editor):
|
||
|
|
query = Query(model)
|
||
|
|
where = query.build_where(self.constraint)
|
||
|
|
connection = schema_editor.connection
|
||
|
|
compiler = connection.ops.compiler('SQLCompiler')(query, connection, 'default')
|
||
|
|
sql, params = where.as_sql(compiler, connection)
|
||
|
|
params = tuple(schema_editor.quote_value(p) for p in params)
|
||
|
|
return schema_editor.sql_check % {
|
||
|
|
'name': schema_editor.quote_name(self.name),
|
||
|
|
'check': sql % params,
|
||
|
|
}
|
||
|
|
|
||
|
|
def create_sql(self, model, schema_editor):
|
||
|
|
sql = self.constraint_sql(model, schema_editor)
|
||
|
|
return schema_editor.sql_create_check % {
|
||
|
|
'table': schema_editor.quote_name(model._meta.db_table),
|
||
|
|
'check': sql,
|
||
|
|
}
|
||
|
|
|
||
|
|
def remove_sql(self, model, schema_editor):
|
||
|
|
quote_name = schema_editor.quote_name
|
||
|
|
return schema_editor.sql_delete_check % {
|
||
|
|
'table': quote_name(model._meta.db_table),
|
||
|
|
'name': quote_name(self.name),
|
||
|
|
}
|
||
|
|
|
||
|
|
def __repr__(self):
|
||
|
|
return "<%s: constraint='%s' name='%s'>" % (self.__class__.__name__, self.constraint, self.name)
|
||
|
|
|
||
|
|
def __eq__(self, other):
|
||
|
|
return (
|
||
|
|
isinstance(other, CheckConstraint) and
|
||
|
|
self.name == other.name and
|
||
|
|
self.constraint == other.constraint
|
||
|
|
)
|
||
|
|
|
||
|
|
def deconstruct(self):
|
||
|
|
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
|
||
|
|
path = path.replace('django.db.models.constraints', 'django.db.models')
|
||
|
|
return (path, (), {'constraint': self.constraint, 'name': self.name})
|
||
|
|
|
||
|
|
def clone(self):
|
||
|
|
_, args, kwargs = self.deconstruct()
|
||
|
|
return self.__class__(*args, **kwargs)
|