Django使用原生SQL查询数据库详解

for blog in Blog.objects.raw("select * from blog_blog"):
    print(blog)

for blog in Blog.objects.raw("select * from blog_entry"):
    print(blog.__dict__)  # __dict__ 输出的都是 blog_entry 的字段

for item in Blog.objects.raw("select id from blog_blog"):
    print(item.__dict__)
    print(item.id, item.name)
    print(item.__dict__)

{'_state': <django.db.models.base.ModelState object at 0x7fbd4165b6a0>, 'id': 2}
2 hunter
{'_state': <django.db.models.base.ModelState object at 0x7fbd4165b6a0>, 'id': 2, 'name': 'hunter'}

for blog in Blog.objects.raw("select name from blog_blog"):
    print(blog.__dict__)

entry = Entry.objects.raw("select *, date_format(pub_date, '%%Y-%%m') as date_1 from blog_entry")[0]
print(entry.date_1)

name = "python"
Blog.objects.raw("select * from blog_blog where name = '%s'", [name])

from django.db import connection


def 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

cursor.execute("SELECT foo FROM bar WHERE baz = '30%'")
cursor.execute("SELECT foo FROM bar WHERE baz = '30%%' AND id = %s", [self.id])

def dictfetchall(cursor):
    "Return all rows from a cursor as a dict"
    columns = [col[0] for col in cursor.description]
    return [
        dict(zip(columns, row))
        for row in cursor.fetchall()
    ]

def dictfetchall(cursor):
    "Return all rows from a cursor as a dict"
    columns = [col[0] for col in cursor.description]
    return [
        dict(zip(columns, row))
        for row in cursor.fetchall()
    ]

with connection.cursor() as cursor:
	sql = "select id, name from blog_blog"
	cursor.execute(sql)
	results = dictfetchall(cursor)

print(results)

# 返回的结果：
# [{'id': 20, 'name': 'name_3'}, {'id': 21, 'name': 'name_4'}, {'id': 1, 'name': 'name_5'}]

with connection.cursor() as cursor:
	cursor.execute()

c = connection.cursor()
try:
    c.execute(...)
finally:
    c.close()

from django.db import connections
with connections['my_db_alias'].cursor() as cursor:
    pass