61数据库6_SQLAlchemy

目录

1、declare a  mapping&＃xff1a;... 2

2、connecting&＃xff1a;... 2

3、create a schema&＃xff1a;... 3

4、creating a session&＃xff1a;... 4

5、create an instance of the mapped class&＃xff1a;... 4

6、adding and updating&＃xff1a;... 6

SQLAlchemy&＃xff1a;

是一个ORM框架&＃xff1b;

大量使用元编程&＃xff1b;

编程时&＃xff0c;先对象&关系映射&＃xff0c;才能操作DB&＃xff0c;已成为工业标准&＃xff1b;

https://www.sqlalchemy.org/

https://docs.sqlalchemy.org/en/latest/   #Read this first

https://docs.sqlalchemy.org/en/latest/orm/tutorial.html

pip install sqlalchemy

pip show sqlalchemy

> import sqlalchemy

> sqlalchemy.__version__   #version check

开发中&＃xff0c;一般都采用ORM框架&＃xff0c;这样就可使用对象操作表了&＃xff1b;

定义表映射的类&＃xff0c;使用Column的描述器定义类属性&＃xff0c;使用ForeignKey定义外键约束&＃xff1b;

如果在一个对象中&＃xff0c;想查看其它表对象的内容&＃xff0c;就要使用relationship来定义关系&＃xff1b;

是否使用FK&＃xff1f;

支持&＃xff0c;力挺派&＃xff0c;能使数据保证完整性、一致性&＃xff1b;

不支持&＃xff0c;嫌弃派&＃xff0c;开发难度增加&＃xff0c;大量数据时影响插入、修改、删除的效率&＃xff1b;

通常要在业务层保证数据一致性&＃xff08;事务&＃xff09;&＃xff1b;

注&＃xff1a;

账号密码授权&＃xff0c;若为前端用户&＃xff0c;仅用来查数据&＃xff0c;用grant select即可&＃xff0c;不要grant all&＃xff1b;

UML&＃xff0c;统一建模语言&＃xff1b;

navicat mysql&＃xff0c;右键库或表&＃xff0c;转储SQL文件&＃xff0c;结构和数据&＃xff1b;若仅导出结构&＃xff0c;导出前要删除相关表中数据&＃xff1b;

oralce中没有自增&＃xff0c;用到sequence&＃xff0c;from sqlalchemy import Sequence

创建映射&＃xff1a;

创建基类Base&＃xff0c;便于实体类继承&＃xff1b;

创建实体类&＃xff0c;Student表&＃xff1b;

from sqlalchemy.ext.declarative import declarative_base

Base &＃61; declarative_base()   #基类&＃xff0c;创建基类&＃xff0c;一次性的

from sqlalchemy import Column, Integer, String

class Student(Base):   #实体类&＃xff0c;declare a mapping

    __tablename__ &＃61; &＃39;student&＃39;   #指定表名&＃xff0c;必须写&＃xff0c;防止忘记对应的表

    id &＃61; Column(&＃39;id&＃39;, Integer, primary_key&＃61;True, autoincrement&＃61;True))   #定义属性对应字段&＃xff0c;第1参数是字段名&＃xff0c;如果和属性名一致可省&＃xff0c;如果和属性名不一致要指定&＃xff1b;Column类指定对应的字段&＃xff0c;必须指定&＃xff0c;Column即上例的Field&＃xff1b;此处&＃39;id&＃39;可省&＃xff0c;Integer为type不能省

    name &＃61; Column(String(64), nullable&＃61;False)

    age &＃61; Column(Integer)

    def __repr__(self):

        return &＃39;<{} id:{} name:{} age:{}>&＃39;.format(self.__class__.__name__, self.id, self.name, self.age)

    __str__ &＃61; __repr__

数据库连接的事情&＃xff0c;交给引擎&＃xff1b;

echo&＃61;True&＃xff0c;引擎是否打印执行的语句&＃xff0c;调试时打开很方便&＃xff1b;

mysqldb的连接&＃xff1a;

mysql&＃43;mysqldb://:&＃64;[:port]/

engine &＃61; sqlalchemy.create_engine(&＃39;mysql&＃43;mysqldb://root:rootqazwsx&＃64;10.113.129.2:3306/test1&＃39;)

pymysql的连接&＃xff1a;

mysql&＃43;pymysql://:&＃64;:/[?]&＃xff0c;options为与DB连接相关的选项

engine &＃61; sqlalchemy.create_engine(&＃39;mysql&＃43;pymysql://root:rootqazwsx&＃64;10.113.129.2:3306/test1&＃39;)

https://docs.sqlalchemy.org/en/latest/core/engines.html

engine-configuration&＃xff1a;

注&＃xff1a;

内部使用了连接池&＃xff1b;

dialect&＃xff0c;方言&＃xff0c;sql差异&＃xff1b;

from sqlalchemy import create_engine

host &＃61; &＃39;10.113.129.2&＃39;

port &＃61; 3306

user &＃61; &＃39;root&＃39;

password &＃61; &＃39;rootqazwsx&＃39;

database &＃61; &＃39;test1&＃39;

conn_str &＃61; &＃39;mysql&＃43;pymysql://{}:{}&＃64;{}:{}/{}&＃39;.format(user, password, host, port, database)

# engine &＃61; create_engine(&＃39;mysql&＃43;pymysql://root:rootqazwsx&＃64;10.113.129.2:3306/test1&＃39;, echo&＃61;True)   #

engine &＃61; create_engine(conn_str, echo&＃61;True)   #引擎&＃xff0c;管理连接池&＃xff0c;connecting&＃xff1b;echo&＃61;True&＃xff0c;执行的语句是否打印&＃xff0c;可在配置文件中全局设置&＃xff0c;调试时打开

Base.metadata.drop_all(engine)   #删除继承自Base的所有表

Base.metadata.create_all(engine)   #create a schema&＃xff0c;创建继承自Base的所有表&＃xff1b;Base.metadata中有一张表记录着所有用Base创建的实体类&＃xff08;实体类继承自Base)&＃xff0c;遍历所有实体类&＃xff0c;将查到的定义信息填到创建表的语句中&＃xff1b;engine的echo&＃61;True&＃xff0c;打开&＃xff0c;执行后会有建表语句&＃xff1b;创建表&＃xff0c;共用的功能&＃xff0c;而子类上是个性化的功能

注&＃xff1a;

生产很少这样创建表&＃xff0c;都是系统上线时由脚本生成&＃xff0c;如用navicat mysql在测试里右键库或表&＃xff0c;转储SQL文件&＃xff0c;再导入到生产里&＃xff1b;

生产很少删除表&＃xff0c;废弃都不能删除&＃xff1b;

在一个会话中操作数据库&＃xff0c;会话建立在连接上&＃xff0c;连接被引擎管理&＃xff1b;

from sqlalchemy.orm import sessionmaker

Session &＃61; sessionmaker(bind&＃61;engine)   #方式一&＃xff1b;返回类&＃xff1b;另&＃xff0c;autoflush&＃61;False&＃xff0c;autocommit&＃61;False

session &＃61; Session()   #实例化&＃xff0c;session.add()&＃xff0c;session.add_all()&＃xff0c;session.commit()&＃xff0c;session.rollback()&＃xff0c;session.query()&＃xff0c;session.cursor&＃xff0c;session.execute()

# Session &＃61; sessionmaker()   #方式二

# session &＃61; Session(bind&＃61;engine)

注&＃xff1a;

class sessionmaker(_SessionClassMethods):

    def __init__(self, bind&＃61;None, class_&＃61;Session, autoflush&＃61;True,

                 autocommit&＃61;False,

                 expire_on_commit&＃61;True,

                 info&＃61;None, **kw):

例&＃xff0c;增&＃xff1a;

try:

    stu1 &＃61; Student()

    stu1.name &＃61; &＃39;tom&＃39;   #属性赋值

    stu1.age &＃61; 20

    # student.id &＃61; 100   #有自增字段和有默认值的可不加

    # session.add(stu1)   #状态为pending

    stu2 &＃61; Student(name&＃61;&＃39;jerry&＃39;, age&＃61;18)   #构造的时候传入

    session.add_all([stu1, stu2])   #状态为pending

    # lst &＃61; []

    # for i in range(10):

    #     stu &＃61; Student()

    #     stu.name &＃61; &＃39;jessica&＃39; &＃43; str(i)

    #     stu.age &＃61; 20 &＃43; i

    #     lst.append(stu)

    # session.add_all(lst)

    session.commit()

except Exception as e:

    print(e)

    session.rollback()

finally:

    pass

输出&＃xff1a;

2018-10-10 17:04:18,319 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE &＃39;sql_mode&＃39;

2018-10-10 17:04:18,320 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,333 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2018-10-10 17:04:18,333 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,355 INFO sqlalchemy.engine.base.Engine show collation where &＃96;Charset&＃96; &＃61; &＃39;utf8&＃39; and &＃96;Collation&＃96; &＃61; &＃39;utf8_bin&＃39;

2018-10-10 17:04:18,355 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,371 INFO sqlalchemy.engine.base.Engine SELECT CAST(&＃39;test plain returns&＃39; AS CHAR(60)) AS anon_1

2018-10-10 17:04:18,371 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,382 INFO sqlalchemy.engine.base.Engine SELECT CAST(&＃39;test unicode returns&＃39; AS CHAR(60)) AS anon_1

2018-10-10 17:04:18,382 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,393 INFO sqlalchemy.engine.base.Engine SELECT CAST(&＃39;test collated returns&＃39; AS CHAR CHARACTER SET utf8) COLLATE utf8_bin AS anon_1

2018-10-10 17:04:18,393 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,414 INFO sqlalchemy.engine.base.Engine DESCRIBE &＃96;student&＃96;

2018-10-10 17:04:18,414 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,430 INFO sqlalchemy.engine.base.Engine

DROP TABLE student

2018-10-10 17:04:18,430 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,447 INFO sqlalchemy.engine.base.Engine COMMIT

2018-10-10 17:04:18,468 INFO sqlalchemy.engine.base.Engine DESCRIBE &＃96;student&＃96;

2018-10-10 17:04:18,468 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,482 INFO sqlalchemy.engine.base.Engine ROLLBACK

2018-10-10 17:04:18,494 INFO sqlalchemy.engine.base.Engine

CREATE TABLE student (

         id INTEGER NOT NULL AUTO_INCREMENT,

         name VARCHAR(64) NOT NULL,

         age INTEGER,

         PRIMARY KEY (id)

)

2018-10-10 17:04:18,494 INFO sqlalchemy.engine.base.Engine {}

2018-10-10 17:04:18,537 INFO sqlalchemy.engine.base.Engine COMMIT

2018-10-10 17:04:18,562 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2018-10-10 17:04:18,563 INFO sqlalchemy.engine.base.Engine INSERT INTO student (name, age) VALUES (%(name)s, %(age)s)

2018-10-10 17:04:18,563 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 20, &＃39;name&＃39;: &＃39;tom&＃39;}

2018-10-10 17:04:18,574 INFO sqlalchemy.engine.base.Engine INSERT INTO student (name, age) VALUES (%(name)s, %(age)s)   #用了参数化查询

2018-10-10 17:04:18,574 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 18, &＃39;name&＃39;: &＃39;jerry&＃39;}

2018-10-10 17:04:18,586 INFO sqlalchemy.engine.base.Engine COMMIT

CRUD操作&＃xff1b;

每一个实体都有一个状态属性_sa_instance_state&＃xff0c;其类型是sqlalchemy.orm.state.InstanceState&＃xff0c;可使用sqlalchemy.inspect(entity)函数查看状态&＃xff1b;

常见的状态有&＃xff1a;

transient&＃xff0c;实体类尚未加入到session中&＃xff0c;同时并没有保存到数据库中&＃xff1b;

pending&＃xff0c;transient的实体被add()到session中&＃xff0c;状态切换为pending&＃xff0c;但还未flush到DB中&＃xff1b;

persistent&＃xff0c;session中的实体对象对应着DB中的真实记录&＃xff0c;pending状态在提交成功后变为persistent状态&＃xff0c;或查询成功返回的实体也是persistent状态&＃xff1b;

deleted&＃xff0c;实体被删除且已flush但未commit完成&＃xff0c;事务提交成功了&＃xff0c;实体变成detached&＃xff0c;事务失败返回persistent状态&＃xff1b;

detached&＃xff0c;删除成功的实体进入这个状态&＃xff1b;

新建一个实体&＃xff0c;状态是transient临时的&＃xff1b;

一旦add()后&＃xff0c;由transient-->pending&＃xff1b;

成功commit()后&＃xff0c;由pending-->persistent&＃xff1b;

成功查询返回的实体对象&＃xff0c;也是persistent&＃xff1b;

persistent状态的实体&＃xff0c;依然是persistent状态&＃xff1b;

persistent状态的实体&＃xff0c;删除后&＃xff0c;已flush但没commit()&＃xff0c;转为deleted&＃xff0c;事务成功提交&＃xff0c;转为detached&＃xff0c;事务提交失败&＃xff0c;转为persistent&＃xff1b;

只有在persistent状态的实体&＃xff0c;才能delete和update&＃xff0c;即删除、修改操作&＃xff0c;&＃xff1b;

例&＃xff0c;commit()后的增&＃xff1a;

try:

    stu1 &＃61; Student()

    stu1.name &＃61; &＃39;tom&＃39;

    stu1.age &＃61; 20

    # student.id &＃61; 100

    print(stu1.id)

    session.add(stu1)

    # stu2 &＃61; Student(name&＃61;&＃39;jerry&＃39;, age&＃61;18)

    # session.add_all([stu1, stu2])

    session.commit()

    print(&＃39;~~~~~~~~~~~~~~~~~~~~~~~~~~~&＃39;)

    print(&＃39;&＃64;&＃64;&＃64;&＃64;&＃64;&＃64;&＃64;&＃39;, stu1.id)

    stu1.age &＃61; 22   #session.commit()后再改&＃xff0c;会先查询

    session.add(stu1)   #再次session.add()和session.commit()&＃xff0c;由于id为PK且自增&＃xff0c;无论有无stu1.age&＃61;22都会新增一条记录&＃xff1b;若id不是自增&＃xff0c;有stu1.age&＃61;22则是update一条记录

    session.commit()   #始终与状态有关&＃xff0c;感知到stu1有变化才会提交&＃xff0c;能否提交成功看stu1有无变化&＃xff0c;有变化了才提交&＃xff08;id为autoincrement&＃xff0c;此例只要执行就会新增一条记录&＃xff09;&＃xff1b;stu1主键没有值&＃xff0c;就是新增&＃xff0c;主键有值&＃xff0c;就是找到对应的记录修改

except Exception as e:

    print(e)

    session.rollback()

finally:

    pass

输出&＃xff1a;

……

2018-10-10 21:20:13,812 INFO sqlalchemy.engine.base.Engine {}

None

2018-10-10 21:20:13,839 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2018-10-10 21:20:13,840 INFO sqlalchemy.engine.base.Engine INSERT INTO student (name, age) VALUES (%(name)s, %(age)s)

2018-10-10 21:20:13,841 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 20, &＃39;name&＃39;: &＃39;tom&＃39;}

2018-10-10 21:20:13,852 INFO sqlalchemy.engine.base.Engine COMMIT

~~~~~~~~~~~~~~~~~~~~~~~~~~~

2018-10-10 21:20:13,881 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2018-10-10 21:20:13,881 INFO sqlalchemy.engine.base.Engine SELECT student.id AS student_id, student.name AS student_name, student.age AS student_age

FROM student

WHERE student.id &＃61; %(param_1)s

2018-10-10 21:20:13,881 INFO sqlalchemy.engine.base.Engine {&＃39;param_1&＃39;: 16}

&＃64;&＃64;&＃64;&＃64;&＃64;&＃64;&＃64; 16

2018-10-10 21:20:13,894 INFO sqlalchemy.engine.base.Engine UPDATE student SET age&＃61;%(age)s WHERE student.id &＃61; %(student_id)s

2018-10-10 21:20:13,894 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 22, &＃39;student_id&＃39;: 16}

2018-10-10 21:20:13,909 INFO sqlalchemy.engine.base.Engine COMMIT

例&＃xff0c;简单查询&＃xff1a;

try:

    queryobj &＃61; session.query(Student).filter(Student.id&＃61;&＃61;8)   #query()方法将实体类传入&＃xff0c;返回类对象&＃xff08;是可迭代对象&＃xff0c;查看源码有__iter__()&＃xff09;&＃xff0c;这时候并不查询&＃xff0c;迭代它就执行sql来查询数据库&＃xff0c;封装数据到指定类的实例&＃xff1b;get()方法使用主键查询&＃xff0c;返回一条传入类的一个实例

    # queryobj &＃61; session.query(Student)   #无条件

         for i in queryobj:

        print(&＃39;########&＃39;, i)

except Exception as e:

    print(e)

输出&＃xff1a;

……

2018-10-10 22:42:32,931 INFO sqlalchemy.engine.base.Engine SELECT student.id AS student_id, student.name AS student_name, student.age AS student_age

FROM student

WHERE student.id &＃61; %(id_1)s

2018-10-10 22:42:32,931 INFO sqlalchemy.engine.base.Engine {&＃39;id_1&＃39;: 8}

########

例&＃xff0c;改&＃xff0c;错误示例&＃xff1a;

try:

    stu1 &＃61; Student()

    stu1.id &＃61; 2   #这种不是改&＃xff0c;而是是一个全新的stu1&＃xff0c;如果该id已有&＃xff0c;会PK冲突&＃xff1b;正确改的做法&＃xff0c;先查再改&＃xff0c;得到PK才能改

    stu1.name &＃61; &＃39;jerry&＃39;

    stu1.age &＃61; 28

    session.add(stu1)

    session.commit()

except Exception as e:

    print(e)

    session.rollback()

finally:

    pass

输出&＃xff1a;

2018-10-11 08:07:21,772 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2018-10-11 08:07:21,773 INFO sqlalchemy.engine.base.Engine INSERT INTO student (id, name, age) VALUES (%(id)s, %(name)s, %(age)s)

2018-10-11 08:07:21,773 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 28, &＃39;id&＃39;: 2, &＃39;name&＃39;: &＃39;jerry&＃39;}

2018-10-11 08:07:21,785 INFO sqlalchemy.engine.base.Engine ROLLBACK

(pymysql.err.IntegrityError) (1062, "Duplicate entry &＃39;2&＃39; for key &＃39;PRIMARY&＃39;") [SQL: &＃39;INSERT INTO student (id, name, age) VALUES (%(id)s, %(name)s, %(age)s)&＃39;] [parameters: {&＃39;age&＃39;: 28, &＃39;id&＃39;: 2, &＃39;name&＃39;: &＃39;jerry&＃39;}]

例&＃xff0c;改&＃xff1a;

先查回来&＃xff0c;修改后&＃xff0c;再提交&＃xff1b;

改不能改PK字段&＃xff1b;

先SELECT再UPDATE&＃xff1b;

try:

    stu1 &＃61; session.query(Student).get(2)

    print(&＃39;$$$$$$$&＃39;, stu1)

    stu1.name &＃61; &＃39;jowin&＃39;

    stu1.age &＃61; 28

    print(&＃39;#######&＃39;, stu1)

    session.add(stu1)

    session.commit()

except Exception as e:

    print(e)

    session.rollback()

finally:

    pass

输出&＃xff1a;

2018-10-11 08:39:56,595 INFO sqlalchemy.engine.base.Engine SELECT student.id AS student_id, student.name AS student_name, student.age AS student_age

FROM student

WHERE student.id &＃61; %(param_1)s

2018-10-11 08:39:56,595 INFO sqlalchemy.engine.base.Engine {&＃39;param_1&＃39;: 2}

$$$$$$$

#######

2018-10-11 08:39:56,607 INFO sqlalchemy.engine.base.Engine UPDATE student SET name&＃61;%(name)s, age&＃61;%(age)s WHERE student.id &＃61; %(student_id)s

2018-10-11 08:39:56,608 INFO sqlalchemy.engine.base.Engine {&＃39;age&＃39;: 28, &＃39;student_id&＃39;: 2, &＃39;name&＃39;: &＃39;jowin&＃39;}

2018-10-11 08:39:56,619 INFO sqlalchemy.engine.base.Engine COMMIT

例&＃xff0c;删&＃xff0c;错误示例&＃xff1a;

try:

    stu1 &＃61; Student(id&＃61;2, name&＃61;&＃39;sam&＃39;, age&＃61;26)

    session.delete(stu1)

    session.commit()

except Exception as e:

    print(e)

    session.rollback()

finally:

    pass

输出&＃xff1a;

Instance &＃39;&＃39; is not persisted   #未持久的异常

例&＃xff0c;删&＃xff1a;

正确做法&＃xff0c;先查再删&＃xff1b;

from sqlalchemy import inspect

try:

    stu1 &＃61; session.query(Student).get(2)

    session.delete(stu1)

    print(&＃39;$$$$$$$$$$$$&＃39;, inspect(stu1))

    session.commit()

    print(&＃39;##########&＃39;, inspect(stu1))

except Exception as e:

    print(e)

    session.rollabck()

finally:

    pass

输出&＃xff1a;

2018-10-11 08:52:12,317 INFO sqlalchemy.engine.base.Engine SELECT student.id AS student_id, student.name AS student_name, student.age AS student_age

FROM student

WHERE student.id &＃61; %(param_1)s

2018-10-11 08:52:12,318 INFO sqlalchemy.engine.base.Engine {&＃39;param_1&＃39;: 2}

$$$$$$$$$$$$

2018-10-11 08:52:12,330 INFO sqlalchemy.engine.base.Engine DELETE FROM student WHERE student.id &＃61; %(id)s

2018-10-11 08:52:12,330 INFO sqlalchemy.engine.base.Engine {&＃39;id&＃39;: 2}

2018-10-11 08:52:12,342 INFO sqlalchemy.engine.base.Engine COMMIT

##########

例&＃xff0c;删&＃xff1a;

from sqlalchemy import inspect

def show(entity):

    ins &＃61; inspect(entity)

    print(&＃39;~~~~~~~~~~~~~~~&＃39;, ins.transient, ins.pending, ins.persistent, ins.detached)

try:

    # print(&＃39;~~~~~~~~~~~~~&＃39;, Student.__dict__)

    stu1 &＃61; session.query(Student).get(4)

    session.delete(stu1)

    # ins &＃61; inspect(stu1)

    # print(&＃39;$$$$$$$$$$$$&＃39;, ins)

    show(stu1)

    session.commit()

    # ins &＃61; inspect(stu1)

    # print(&＃39;##########&＃39;, ins)

    show(stu1)

except Exception as e:

    print(e)

    session.rollabck()

finally:

    pass

输出&＃xff1a;

018-10-11 14:40:28,111 INFO sqlalchemy.engine.base.Engine SELECT student.id AS student_id, student.name AS student_name, student.age AS student_age

FROM student

WHERE student.id &＃61; %(param_1)s

2018-10-11 14:40:28,111 INFO sqlalchemy.engine.base.Engine {&＃39;param_1&＃39;: 4}

~~~~~~~~~~~~~~~ False False True False

2018-10-11 14:40:28,126 INFO sqlalchemy.engine.base.Engine DELETE FROM student WHERE student.id &＃61; %(id)s

2018-10-11 14:40:28,126 INFO sqlalchemy.engine.base.Engine {&＃39;id&＃39;: 4}

2018-10-11 14:40:28,152 INFO sqlalchemy.engine.base.Engine COMMIT

~~~~~~~~~~~~~~~ False False False True