MySQL -如何插入具有多对多关系的表

I have a table of persons. Each person has a property and many persons may have a certain property. So this is a many-to-many relationship. This is the schema:

我有一张桌子。每个人都有自己的财产，很多人都有自己的财产。这是一个多对多关系。这是模式:

CREATE TABLE persons (
  person_id int(11) NOT NULL AUTO_INCREMENT,
  firstname varchar(30) NOT NULL,
  lastname varchar(30) NOT NULL,
  PRIMARY KEY (person_id)
);

CREATE TABLE properties (
  property_id int(11) NOT NULL AUTO_INCREMENT,
  property varchar(254) NOT NULL UNIQUE,
  PRIMARY KEY (property_id)
);

CREATE TABLE has_property (
  person_id int(11) NOT NULL,
  property_id int(11) NOT NULL,
  PRIMARY KEY (person_id,property_id),
  FOREIGN KEY (person_id) REFERENCES persons (person_id),
  FOREIGN KEY (property_id) REFERENCES properties (property_id)
);

Now lets say i want to insert to the database this person:

现在假设我想把这个人插入数据库

• firstname:'John'
• 名字:“约翰”
• lastname:'Doe'
• 姓:“母鹿”
• properties:'property_A','property_B','property_C'
• 属性:‘property_A’,‘property_B’,‘property_C’

persons

人

+-----------+-----------+----------+
| person_id | firstname | lastname |
+-----------+-----------+----------+
|         1 | John      | Doe      |
+-----------+-----------+----------+

properties

属性

+-------------+------------+
| property_id |  property  |
+-------------+------------+
|           1 | property_A |
|           2 | property_B |
|           3 | property_C |
+-------------+------------+

has_property

has_property

+-----------+-------------+
| person_id | property_id |
+-----------+-------------+
|         1 |           1 |
|         1 |           2 |
|         1 |           3 |
+-----------+-------------+

So far the best thing i have thought is to do a regular insert in the persons table:

到目前为止，我认为最好的办法是在人员表中定期插入:

INSERT INTO persons (firstname,lastname) VALUES ('John','Doe');

and then do a select to find the id of the person i just inserted

然后做一个选择，找到我刚才插入的那个人的id

SELECT person_id FROM persons WHERE firstname='John' AND lastname='Doe';

in order to insert into the other two tables (because i need to know the person_id). But i think there must be a better way, isn't it?

为了插入到其他两个表中(因为我需要知道person_id)。但我认为肯定有更好的办法，不是吗?

1 个解决方案

#1

Here is what i ended up doing. I hope it helps someone.

这就是我最后所做的。我希望它能帮助某人。

INSERT INTO persons (firstname,lastname) VALUES ('John','Doe');
SET @person_id = LAST_INSERT_ID();

INSERT IGNORE INTO properties (property) VALUES ('property_A');
SET @property_id = LAST_INSERT_ID();
INSERT INTO has_property (person_id,property_id) VALUES(@person_id, @property_id);

INSERT IGNORE INTO properties (property) VALUES ('property_B');
SET @property_id = LAST_INSERT_ID();
INSERT INTO has_property (person_id,property_id) VALUES(@person_id, @property_id);

INSERT IGNORE INTO properties (property) VALUES ('property_C');
SET @property_id = LAST_INSERT_ID();
INSERT INTO has_property (person_id,property_id) VALUES(@person_id, @property_id);