django怎么执行sql语句

1、Manager.raw(raw_query,params=None,translations=None)>>> for p in Person.objects.raw('SELECT * FROM myapp_person'):... print(p)John SmithJane Jones这个方法接受一个原始的SQL查询，执行它，并返回一个django.db.models.query。RawQuerySet实例。这个RawQuerySet实例可以像普通的QuerySet一样遍历，以提供对象实例。

2、（1）字段匹配>>> Person.objects.raw('''SELECT first AS first_name,... last AS last_name,... bd AS birth_date,... pk AS id,... FROM some_other_table''')>>> name_map = {'first': 'first_name', 'last': 'last_name', 'bd': 'birth_date', 'pk': 'id'}>>> Person.objects.raw('SELECT * FROM some_other_table', translations=name_map)

3、（2）即使没有显示表明查询字段，也可以获取>>> for p in Person.objects.raw('SELECT id, first_name FROM myapp_person'):... print(p.first_name, # This will be retrieved by the original query... p.last_name) # This will be retrieved on demand...John SmithJane Jones

4、（3）执行带参数SQL字符串用%s占位符字典用%(key)s占位符>>> lname = 'Doe'>>> Person.objects.raw('SELECT * FROM myapp_person WHERE last_name = %s', [lname])

5、（4）严禁使用字符串拼接>>> query = 'SELECT * FROM myapp_person WHERE last_name = %s' % lname>>> Person.objects.raw(query)

6、（5）参数不能用引号包裹‘’>>> query = "SELECT * FROM myapp_person WHERE last_name = '%s'"

7、通过connection.cursor()执行SQL对象django.db.connection表示默认的数据库连接。要使用数据库连接，请调用connection.cursor()来获得一个游标对象。然后调用cursor.execute(sql， [params])方法以执行sqlcursor.fetchone()或cursor.fetchall()以返回结果行。from django.db import connectiondef my_custom_sql(self): with connection.cursor() as cursor: cursor.execute("UPDATE bar SET foo = 1 WHERE baz = %s", [self.baz]) cursor.execute("SELECT foo FROM bar WHERE baz = %s", [self.baz]) row = cursor.fetchone() return row

8、（1）传递百分比参数需要写两个百分号cursor.execute("SELECT foo FROM bar WHERE baz = '30%%' AND id = %s", [self.id])

9、（2）cursor碌巫谫浪执行不会返回列名用字典或命名元组def dictfetchall(cursor): "Return all rows from a cursor 锾攒揉敫as a dict" columns = [col[0] for col in cursor.description] return [ dict(zip(columns, row)) for row in cursor.fetchall() ]from collections import namedtupledef namedtuplefetchall(cursor): "Return all rows from a cursor as a namedtuple" desc = cursor.description nt_result = namedtuple('Result', [col[0] for col in desc]) return [nt_result(*row) for row in cursor.fetchall()]>>> cursor.execute("SELECT id, parent_id FROM test LIMIT 2");>>> dictfetchall(cursor)[{'parent_id': None, 'id': 54360982}, {'parent_id': None, 'id': 54360880}]