MySQL多对多：先插入表，然后再插入联结表？

Question

I have 3 tables: persons , places and person_place .

Each person can have many favorite places, just as each place can be "favorited" by many persons/people.

CREATE TABLE persons
(
ID int NOT NULL AUTO_INCREMENT,
name VARCHAR(50) NOT NULL
//some fields omitted
);

CREATE TABLE places 
(
ID int NOT NULL AUTO_INCREMENT,
name VARCHAR(50) NOT NULL,
address VARCHAR(50) NOT NULL
//some fields omitted
);

CREATE TABLE person_place 
(
ID int NOT NULL AUTO_INCREMENT,
personID int NOT NULL, //references persons.id
placeID int NOT NULL //references places.id
)

Let's say a user favorites a new place (by some web page).

How should I insert the new place and then get it's id in order to add the person_place row?

Thank you.

Answer 1

I would wrap the inserts inside a transaction and then use LAST_INSERT_ID() to get the id of the last inserted item.

START TRANSACTION;
INSERT INTO places(name,address) VALUES('someplace', '...');
SET @last_inserted_id = LAST_INSERT_ID();

INSERT INTO person_place (personID, placeID) VALUES (1, @last_inserted_id)

COMMIT;

Answer 2

我相信在MySQL中，您将使用LAST_INSERT_ID（）函数。