Python3-sqlalchemy-orm 多对多关系建表、插入数据、查询数据

现在来设计一个能描述“图书”与“作者”的关系的表结构，需求是

一本书可以有好几个作者一起出版
一个作者可以写好几本书

此时你会发现，用之前学的外键好像没办法实现上面的需求了，因为

当然你更不可以像下面这样干，因为这样就你就相当于有多条书的记录了，太low b了，改书名还得都改。。。

那怎么办呢？此时，我们可以再搞出一张中间表，就可以了

这样就相当于通过book_m2m_author表完成了book表和author表之前的多对多关联

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

import sqlalchemy

from sqlalchemy import create_engine,func

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy.orm import sessionmaker,relationship

from sqlalchemy import Table, Column, Integer,String,DATE, ForeignKey

from sqlalchemy.orm import relationship

engine=create_engine("mysql+pymysql://root:12345678@localhost/news",encoding='utf-8',echo=True)

Base=declarative_base()

#一本书可以有多个作者，一个作者又可以出版多本书

book_m2m_author = Table('book_m2m_author', Base.metadata,

                        Column('book_id',Integer,ForeignKey('books.id')),

                        Column('author_id',Integer,ForeignKey('authors.id')),

                        )

class Book(Base):

    __tablename__ = 'books'

    id = Column(Integer,primary_key=True)

    name = Column(String(64))

    pub_date = Column(DATE)

    authors = relationship('Author',secondary=book_m2m_author,backref='books')

    def __repr__(self):

        return self.name

class Author(Base):

    __tablename__ = 'authors'

    id = Column(Integer, primary_key=True)

    name = Column(String(32))

    def __repr__(self):

        return self.name

Base.metadata.create_all(engine)

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

from orm_m2m import orm_m2m

from sqlalchemy.orm import sessionmaker

Session_class=sessionmaker(bind=orm_many_fk.engine) #创建与数据库的链接

session= Session_class() #生成session实例 #cursor

/Users/drizzle/PycharmProjects/2018-12-03/venv/bin/python /Users/drizzle/PycharmProjects/2018-12-03/orm_m2m/orm_m2m.py

2019-01-08 19:35:48,687 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'sql_mode'

2019-01-08 19:35:48,687 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,689 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'lower_case_table_names'

2019-01-08 19:35:48,689 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,691 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2019-01-08 19:35:48,691 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,692 INFO sqlalchemy.engine.base.Engine show collation where `Charset` = 'utf8mb4' and `Collation` = 'utf8mb4_bin'

2019-01-08 19:35:48,692 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,694 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS CHAR(60)) AS anon_1

2019-01-08 19:35:48,695 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,695 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS CHAR(60)) AS anon_1

2019-01-08 19:35:48,695 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,696 INFO sqlalchemy.engine.base.Engine SELECT CAST('test collated returns' AS CHAR CHARACTER SET utf8mb4) 
COLLATE utf8mb4_bin AS anon_1

2019-01-08 19:35:48,696 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,697 INFO sqlalchemy.engine.base.Engine DESCRIBE `book_m2m_author`

2019-01-08 19:35:48,697 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,698 INFO sqlalchemy.engine.base.Engine ROLLBACK

2019-01-08 19:35:48,698 INFO sqlalchemy.engine.base.Engine DESCRIBE `books`

2019-01-08 19:35:48,698 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,699 INFO sqlalchemy.engine.base.Engine ROLLBACK

2019-01-08 19:35:48,699 INFO sqlalchemy.engine.base.Engine DESCRIBE `authors`

2019-01-08 19:35:48,699 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,699 INFO sqlalchemy.engine.base.Engine ROLLBACK

2019-01-08 19:35:48,700 INFO sqlalchemy.engine.base.Engine

CREATE TABLE books (

    id INTEGER NOT NULL AUTO_INCREMENT,

    name VARCHAR(64),

    pub_date DATE,

    PRIMARY KEY (id)

)

2019-01-08 19:35:48,700 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,793 INFO sqlalchemy.engine.base.Engine COMMIT

2019-01-08 19:35:48,794 INFO sqlalchemy.engine.base.Engine

CREATE TABLE authors (

    id INTEGER NOT NULL AUTO_INCREMENT,

    name VARCHAR(32),

    PRIMARY KEY (id)

)

2019-01-08 19:35:48,794 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,800 INFO sqlalchemy.engine.base.Engine COMMIT

2019-01-08 19:35:48,802 INFO sqlalchemy.engine.base.Engine

CREATE TABLE book_m2m_author (

    book_id INTEGER,

    author_id INTEGER,

    FOREIGN KEY(book_id) REFERENCES books (id),

    FOREIGN KEY(author_id) REFERENCES authors (id)

)

2019-01-08 19:35:48,802 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:35:48,811 INFO sqlalchemy.engine.base.Engine COMMIT

Process finished with exit code 0

mysql> show tables;

+-----------------+

| Tables_in_news  |

+-----------------+

| address         |

| authors         |

| book_m2m_author |

| books           |

| customer        |

| student         |

| study_record    |

| user            |

+-----------------+

8 rows in set (0.00 sec)

mysql> show create table authors;

+---------+--------------------------------------------------------------+

| Table   | Create Table                                                                                                                                                                                |

+---------+--------------------------------------------------------------+

| authors | CREATE TABLE `authors` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` varchar(32) DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |

+---------+-------------------------------------------------------------+

1 row in set (0.00 sec)

mysql> show create table book_m2m_author;

+-----------------+--------------------------------------------------------------------------+

| Table           | Create Table                                                                                                                                                                                                                                                                                                                                                                                                                 |

+-----------------+--------------------------------------------------------------------------+

| book_m2m_author | CREATE TABLE `book_m2m_author` (

  `book_id` int(11) DEFAULT NULL,

  `author_id` int(11) DEFAULT NULL,

  KEY `book_id` (`book_id`),

  KEY `author_id` (`author_id`),

  CONSTRAINT `book_m2m_author_ibfk_1` FOREIGN KEY (`book_id`) REFERENCES `books` (`id`),

  CONSTRAINT `book_m2m_author_ibfk_2` FOREIGN KEY (`author_id`) REFERENCES `authors` (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |

+-----------------+-------------------------------------------------------------------------+

1 row in set (0.00 sec)

mysql> show create table books;

+-------+-------------------------------------------------------------+

| Table | Create Table                                                                                                                                                                                                              |

+-------+-------------------------------------------------------------+

| books | CREATE TABLE `books` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` varchar(64) DEFAULT NULL,

  `pub_date` date DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |

+---------------------------------------------------------------------+

mysql> desc book_m2m_author;
+-----------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+---------+------+-----+---------+-------+
| book_id | int(11) | YES | MUL | NULL | |
| author_id | int(11) | YES | MUL | NULL | |
+-----------+---------+------+-----+---------+-------+
2 rows in set (0.00 sec)

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

from m2m import orm_m2m

from sqlalchemy.orm import sessionmaker

Session_class=sessionmaker(bind=orm_m2m.engine) #创建与数据库的链接

session= Session_class() #生成session实例 #cursor

#插入数据

b1= orm_m2m.Book(name="learn python with Alex", pub_date="2019-01-08")

b2= orm_m2m.Book(name="learn JAVA with Alex", pub_date="2019-01-09")

b3= orm_m2m.Book(name="learn LINUX with Alex", pub_date="2019-01-10")

a1= orm_m2m.Author(name="Alex")

a2= orm_m2m.Author(name="Jack")

a3= orm_m2m.Author(name="Eric")

b1.authors=[a1,a3]

b3.authors=[a1,a2,a3]

session.add_all([b1,b2,b3,a1,a2,a3])

session.commit()

/Users/drizzle/PycharmProjects/2018-12-03/venv/bin/python /Users/drizzle/PycharmProjects/2018-12-03/m2m/orm_m2m_api.py

2019-01-08 19:54:48,757 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'sql_mode'

2019-01-08 19:54:48,757 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,759 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'lower_case_table_names'

2019-01-08 19:54:48,759 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,760 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2019-01-08 19:54:48,761 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,761 INFO sqlalchemy.engine.base.Engine show collation where `Charset` = 'utf8mb4' and `Collation` = 'utf8mb4_bin'

2019-01-08 19:54:48,761 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,764 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS CHAR(60)) AS anon_1

2019-01-08 19:54:48,764 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,765 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS CHAR(60)) AS anon_1

2019-01-08 19:54:48,765 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,765 INFO sqlalchemy.engine.base.Engine SELECT CAST('test collated returns' AS CHAR CHARACTER SET utf8mb4) 
COLLATE utf8mb4_bin AS anon_1

2019-01-08 19:54:48,765 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,767 INFO sqlalchemy.engine.base.Engine DESCRIBE `book_m2m_author`

2019-01-08 19:54:48,767 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,768 INFO sqlalchemy.engine.base.Engine DESCRIBE `books`

2019-01-08 19:54:48,768 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,769 INFO sqlalchemy.engine.base.Engine DESCRIBE `authors`

2019-01-08 19:54:48,769 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:54:48,777 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2019-01-08 19:54:48,777 INFO sqlalchemy.engine.base.Engine INSERT INTO authors (name) VALUES (%(name)s)

2019-01-08 19:54:48,777 INFO sqlalchemy.engine.base.Engine {'name': 'Alex'}

2019-01-08 19:54:48,778 INFO sqlalchemy.engine.base.Engine INSERT INTO authors (name) VALUES (%(name)s)

2019-01-08 19:54:48,778 INFO sqlalchemy.engine.base.Engine {'name': 'Jack'}

2019-01-08 19:54:48,779 INFO sqlalchemy.engine.base.Engine INSERT INTO authors (name) VALUES (%(name)s)

2019-01-08 19:54:48,779 INFO sqlalchemy.engine.base.Engine {'name': 'Eric'}

2019-01-08 19:54:48,780 INFO sqlalchemy.engine.base.Engine INSERT INTO books (name, pub_date) VALUES (%(name)s, %(pub_date)s)

2019-01-08 19:54:48,780 INFO sqlalchemy.engine.base.Engine {'name': 'learn python with Alex', 'pub_date': '2019-01-08'}

2019-01-08 19:54:48,780 INFO sqlalchemy.engine.base.Engine INSERT INTO books (name, pub_date) VALUES (%(name)s, %(pub_date)s)

2019-01-08 19:54:48,781 INFO sqlalchemy.engine.base.Engine {'name': 'learn LINUX with Alex', 'pub_date': '2019-01-10'}

2019-01-08 19:54:48,781 INFO sqlalchemy.engine.base.Engine INSERT INTO books (name, pub_date) VALUES (%(name)s, %(pub_date)s)

2019-01-08 19:54:48,781 INFO sqlalchemy.engine.base.Engine {'name': 'learn JAVA with Alex', 'pub_date': '2019-01-09'}

2019-01-08 19:54:48,782 INFO sqlalchemy.engine.base.Engine INSERT INTO book_m2m_author (book_id, author_id) VALUES (%(book_id)s, %(author_id)s)

2019-01-08 19:54:48,782 INFO sqlalchemy.engine.base.Engine ({'book_id': 2, 'author_id': 1}, {'book_id': 2, 'author_id': 2}, 
{'book_id': 2, 'author_id': 3}, {'book_id': 1, 'author_id': 1}, {'book_id': 1, 'author_id': 3})

2019-01-08 19:54:48,783 INFO sqlalchemy.engine.base.Engine COMMIT

Process finished with exit code 0

mysql> select * from authors;

+----+------+

| id | name |

+----+------+

|  1 | Alex |

|  2 | Jack |

|  3 | Eric |

+----+------+

3 rows in set (0.00 sec)

mysql> select * from book_m2m_author;

+---------+-----------+

| book_id | author_id |

+---------+-----------+

|       2 |         1 |

|       2 |         2 |

|       2 |         3 |

|       1 |         1 |

|       1 |         3 |

+---------+-----------+

5 rows in set (0.00 sec)

mysql> select * from books;

+----+------------------------+------------+

| id | name                   | pub_date   |

+----+------------------------+------------+

|  1 | learn python with Alex | 2019-01-08 |

|  2 | learn LINUX with Alex  | 2019-01-10 |

|  3 | learn JAVA with Alex   | 2019-01-09 |

+----+------------------------+------------+

3 rows in set (0.00 sec)

#查询

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

from m2m import orm_m2m

from sqlalchemy.orm import sessionmaker

Session_class=sessionmaker(bind=orm_m2m.engine) #创建与数据库的链接

session= Session_class() #生成session实例 #cursor

#插入数据

#b1= orm_m2m.Book(name="learn python with Alex", pub_date="2019-01-08")#

#b2= orm_m2m.Book(name="learn JAVA with Alex", pub_date="2019-01-09")

#b3= orm_m2m.Book(name="learn LINUX with Alex", pub_date="2019-01-10")

#

#a1= orm_m2m.Author(name="Alex")

#a2= orm_m2m.Author(name="Jack")

#a3= orm_m2m.Author(name="Eric")

#

#b1.authors=[a1,a3]

#b3.authors=[a1,a2,a3]

#

#session.add_all([b1,b2,b3,a1,a2,a3])

#查询数据

author_obj=session.query(orm_m2m.Author).filter(orm_m2m.Author.name=="alex").first()

print(author_obj.books)

session.commit()

/Users/drizzle/PycharmProjects/2018-12-03/venv/bin/python /Users/drizzle/PycharmProjects/2018-12-03/m2m/orm_m2m_api.py

2019-01-08 19:59:34,860 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'sql_mode'

2019-01-08 19:59:34,860 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,862 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'lower_case_table_names'

2019-01-08 19:59:34,862 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,864 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2019-01-08 19:59:34,864 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,865 INFO sqlalchemy.engine.base.Engine show collation where `Charset` = 'utf8mb4' and `Collation` = 'utf8mb4_bin'

2019-01-08 19:59:34,865 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,868 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS CHAR(60)) AS anon_1

2019-01-08 19:59:34,868 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,869 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS CHAR(60)) AS anon_1

2019-01-08 19:59:34,869 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,870 INFO sqlalchemy.engine.base.Engine SELECT CAST('test collated returns' AS CHAR CHARACTER SET utf8mb4) 
COLLATE utf8mb4_bin AS anon_1

2019-01-08 19:59:34,870 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,871 INFO sqlalchemy.engine.base.Engine DESCRIBE `book_m2m_author`

2019-01-08 19:59:34,871 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,872 INFO sqlalchemy.engine.base.Engine DESCRIBE `books`

2019-01-08 19:59:34,872 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,873 INFO sqlalchemy.engine.base.Engine DESCRIBE `authors`

2019-01-08 19:59:34,873 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 19:59:34,879 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2019-01-08 19:59:34,880 INFO sqlalchemy.engine.base.Engine SELECT authors.id AS authors_id, authors.name AS authors_name

FROM authors

WHERE authors.name = %(name_1)s

 LIMIT %(param_1)s

2019-01-08 19:59:34,880 INFO sqlalchemy.engine.base.Engine {'name_1': 'alex', 'param_1': 1}

2019-01-08 19:59:34,882 INFO sqlalchemy.engine.base.Engine SELECT books.id AS books_id, books.name AS books_name,
 books.pub_date AS books_pub_date

FROM books, book_m2m_author

WHERE %(param_1)s = book_m2m_author.author_id AND books.id = book_m2m_author.book_id

2019-01-08 19:59:34,882 INFO sqlalchemy.engine.base.Engine {'param_1': 1}

[learn LINUX with Alex, learn python with Alex]

2019-01-08 19:59:34,883 INFO sqlalchemy.engine.base.Engine COMMIT

Process finished with exit code 0

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

from m2m import orm_m2m

from sqlalchemy.orm import sessionmaker

Session_class=sessionmaker(bind=orm_m2m.engine) #创建与数据库的链接

session= Session_class() #生成session实例 #cursor

#插入数据

#b1= orm_m2m.Book(name="learn python with Alex", pub_date="2019-01-08")#

#b2= orm_m2m.Book(name="learn JAVA with Alex", pub_date="2019-01-09")

#b3= orm_m2m.Book(name="learn LINUX with Alex", pub_date="2019-01-10")

#

#a1= orm_m2m.Author(name="Alex")

#a2= orm_m2m.Author(name="Jack")

#a3= orm_m2m.Author(name="Eric")

#

#b1.authors=[a1,a3]

#b3.authors=[a1,a2,a3]

#

#session.add_all([b1,b2,b3,a1,a2,a3])

#查询数据

author_obj=session.query(orm_m2m.Author).filter(orm_m2m.Author.name=="alex").first()

print(author_obj.books)

book_obj=session.query(orm_m2m.Book).filter(orm_m2m.Book.id==2).first()

print(book_obj)

session.commit()

/Users/drizzle/PycharmProjects/2018-12-03/venv/bin/python /Users/drizzle/PycharmProjects/2018-12-03/m2m/orm_m2m_api.py

2019-01-08 20:03:36,934 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'sql_mode'

2019-01-08 20:03:36,934 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,936 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'lower_case_table_names'

2019-01-08 20:03:36,936 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,937 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2019-01-08 20:03:36,937 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,938 INFO sqlalchemy.engine.base.Engine show collation where `Charset` = 'utf8mb4' and `Collation` = 'utf8mb4_bin'

2019-01-08 20:03:36,938 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,941 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS CHAR(60)) AS anon_1

2019-01-08 20:03:36,941 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,942 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS CHAR(60)) AS anon_1

2019-01-08 20:03:36,942 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,942 INFO sqlalchemy.engine.base.Engine SELECT CAST('test collated returns' AS CHAR CHARACTER SET utf8mb4) 
COLLATE utf8mb4_bin AS anon_1

2019-01-08 20:03:36,942 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,943 INFO sqlalchemy.engine.base.Engine DESCRIBE `book_m2m_author`

2019-01-08 20:03:36,943 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,945 INFO sqlalchemy.engine.base.Engine DESCRIBE `books`

2019-01-08 20:03:36,945 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,946 INFO sqlalchemy.engine.base.Engine DESCRIBE `authors`

2019-01-08 20:03:36,946 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:03:36,953 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2019-01-08 20:03:36,953 INFO sqlalchemy.engine.base.Engine SELECT authors.id AS authors_id, authors.name AS authors_name

FROM authors

WHERE authors.name = %(name_1)s

 LIMIT %(param_1)s

2019-01-08 20:03:36,953 INFO sqlalchemy.engine.base.Engine {'name_1': 'alex', 'param_1': 1}

2019-01-08 20:03:36,955 INFO sqlalchemy.engine.base.Engine SELECT books.id AS books_id, books.name AS books_name, 
books.pub_date AS books_pub_date

FROM books, book_m2m_author

WHERE %(param_1)s = book_m2m_author.author_id AND books.id = book_m2m_author.book_id

2019-01-08 20:03:36,955 INFO sqlalchemy.engine.base.Engine {'param_1': 1}

[learn LINUX with Alex, learn python with Alex]

2019-01-08 20:03:36,957 INFO sqlalchemy.engine.base.Engine SELECT books.id AS books_id, books.name AS books_name, 
books.pub_date AS books_pub_date

FROM books

WHERE books.id = %(id_1)s

 LIMIT %(param_1)s

2019-01-08 20:03:36,957 INFO sqlalchemy.engine.base.Engine {'id_1': 2, 'param_1': 1}

learn LINUX with Alex

2019-01-08 20:03:36,958 INFO sqlalchemy.engine.base.Engine COMMIT

Process finished with exit code 0

#-*-coding:utf-8-*-

#__author__ = "logan.xu"

from m2m import orm_m2m

from sqlalchemy.orm import sessionmaker

Session_class=sessionmaker(bind=orm_m2m.engine) #创建与数据库的链接

session= Session_class() #生成session实例 #cursor

#插入数据

#b1= orm_m2m.Book(name="learn python with Alex", pub_date="2019-01-08")#

#b2= orm_m2m.Book(name="learn JAVA with Alex", pub_date="2019-01-09")

#b3= orm_m2m.Book(name="learn LINUX with Alex", pub_date="2019-01-10")

#

#a1= orm_m2m.Author(name="Alex")

#a2= orm_m2m.Author(name="Jack")

#a3= orm_m2m.Author(name="Eric")

#

#b1.authors=[a1,a3]

#b3.authors=[a1,a2,a3]

#

#session.add_all([b1,b2,b3,a1,a2,a3])

#查询数据

author_obj=session.query(orm_m2m.Author).filter(orm_m2m.Author.name=="alex").first()

print(author_obj.books)

book_obj=session.query(orm_m2m.Book).filter(orm_m2m.Book.id==2).first()

print(book_obj.authors)

session.commit()

/Users/drizzle/PycharmProjects/2018-12-03/venv/bin/python /Users/drizzle/PycharmProjects/2018-12-03/m2m/orm_m2m_api.py

2019-01-08 20:04:49,122 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'sql_mode'

2019-01-08 20:04:49,122 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,124 INFO sqlalchemy.engine.base.Engine SHOW VARIABLES LIKE 'lower_case_table_names'

2019-01-08 20:04:49,124 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,126 INFO sqlalchemy.engine.base.Engine SELECT DATABASE()

2019-01-08 20:04:49,126 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,127 INFO sqlalchemy.engine.base.Engine show collation where `Charset` = 'utf8mb4' and `Collation` = 'utf8mb4_bin'

2019-01-08 20:04:49,127 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,130 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS CHAR(60)) AS anon_1

2019-01-08 20:04:49,130 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,131 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS CHAR(60)) AS anon_1

2019-01-08 20:04:49,131 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,131 INFO sqlalchemy.engine.base.Engine SELECT CAST('test collated returns' AS CHAR CHARACTER SET utf8mb4) 
COLLATE utf8mb4_bin AS anon_1

2019-01-08 20:04:49,131 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,132 INFO sqlalchemy.engine.base.Engine DESCRIBE `book_m2m_author`

2019-01-08 20:04:49,132 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,133 INFO sqlalchemy.engine.base.Engine DESCRIBE `books`

2019-01-08 20:04:49,133 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,135 INFO sqlalchemy.engine.base.Engine DESCRIBE `authors`

2019-01-08 20:04:49,135 INFO sqlalchemy.engine.base.Engine {}

2019-01-08 20:04:49,141 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)

2019-01-08 20:04:49,141 INFO sqlalchemy.engine.base.Engine SELECT authors.id AS authors_id, authors.name AS authors_name

FROM authors

WHERE authors.name = %(name_1)s

 LIMIT %(param_1)s

2019-01-08 20:04:49,141 INFO sqlalchemy.engine.base.Engine {'name_1': 'alex', 'param_1': 1}

2019-01-08 20:04:49,143 INFO sqlalchemy.engine.base.Engine SELECT books.id AS books_id, books.name AS books_name, 
books.pub_date AS books_pub_date

FROM books, book_m2m_author

WHERE %(param_1)s = book_m2m_author.author_id AND books.id = book_m2m_author.book_id

2019-01-08 20:04:49,143 INFO sqlalchemy.engine.base.Engine {'param_1': 1}

[learn LINUX with Alex, learn python with Alex]

2019-01-08 20:04:49,145 INFO sqlalchemy.engine.base.Engine SELECT books.id AS books_id, books.name AS books_name, 
books.pub_date AS books_pub_date

FROM books

WHERE books.id = %(id_1)s

 LIMIT %(param_1)s

2019-01-08 20:04:49,145 INFO sqlalchemy.engine.base.Engine {'id_1': 2, 'param_1': 1}

2019-01-08 20:04:49,146 INFO sqlalchemy.engine.base.Engine SELECT authors.id AS authors_id, authors.name AS authors_name

FROM authors, book_m2m_author

WHERE %(param_1)s = book_m2m_author.book_id AND authors.id = book_m2m_author.author_id

2019-01-08 20:04:49,146 INFO sqlalchemy.engine.base.Engine {'param_1': 2}

[Alex, Jack, Eric]

2019-01-08 20:04:49,147 INFO sqlalchemy.engine.base.Engine COMMIT

Process finished with exit code 0

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