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mysql存放數(shù)組

當(dāng)我們需要在MySQL中存儲(chǔ)數(shù)據(jù)的時(shí)候,通常會(huì)使用表格來(lái)進(jìn)行操作。而在表格中,每一行都可以存儲(chǔ)一個(gè)記錄,每個(gè)記錄由多個(gè)字段組成。在某些情況下,我們需要存儲(chǔ)一個(gè)數(shù)組,即多個(gè)值,這時(shí)候該怎么辦呢?

MySQL是支持存儲(chǔ)數(shù)組的,通常會(huì)有兩種方式:使用JSON數(shù)據(jù)類型或使用多對(duì)多關(guān)系表。下面我們來(lái)分別介紹一下。

JSON數(shù)據(jù)類型存儲(chǔ)示例:
CREATE TABLE users (
id INT NOT NULL AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
hobbies JSON,
PRIMARY KEY (id)
);
INSERT INTO users (name, hobbies) VALUES ('Tom', '["basketball", "reading"]');
INSERT INTO users (name, hobbies) VALUES ('Lucy', '["swimming", "movies", "travel"]');

在這個(gè)示例中,我們創(chuàng)建了一個(gè)名為users的表格,其中包含了id、name、hobbies三個(gè)字段。hobbies采用JSON數(shù)據(jù)類型,可以存儲(chǔ)多個(gè)值。在插入數(shù)據(jù)時(shí),我們可以直接使用JSON格式的數(shù)組進(jìn)行插入。查詢時(shí),也可以使用內(nèi)置的JSON函數(shù)進(jìn)行處理。

多對(duì)多關(guān)系表存儲(chǔ)示例:
CREATE TABLE users (
id INT NOT NULL AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE hobbies (
id INT NOT NULL AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE user_hobbies (
user_id INT,
hobby_id INT,
PRIMARY KEY (user_id, hobby_id),
FOREIGN KEY (user_id) REFERENCES users(id),
FOREIGN KEY (hobby_id) REFERENCES hobbies(id)
);
INSERT INTO users (name) VALUES ('Tom');
INSERT INTO users (name) VALUES ('Lucy');
INSERT INTO hobbies (name) VALUES ('basketball');
INSERT INTO hobbies (name) VALUES ('reading');
INSERT INTO hobbies (name) VALUES ('swimming');
INSERT INTO hobbies (name) VALUES ('movies');
INSERT INTO hobbies (name) VALUES ('travel');
INSERT INTO user_hobbies (user_id, hobby_id) VALUES (1, 1);
INSERT INTO user_hobbies (user_id, hobby_id) VALUES (1, 2);
INSERT INTO user_hobbies (user_id, hobby_id) VALUES (2, 3);
INSERT INTO user_hobbies (user_id, hobby_id) VALUES (2, 4);
INSERT INTO user_hobbies (user_id, hobby_id) VALUES (2, 5);

在這個(gè)示例中,我們創(chuàng)建了三個(gè)表格,分別為users、hobbies、user_hobbies。使用user_hobbies表格建立了users和hobbies之間的多對(duì)多關(guān)系。在查詢時(shí)需要使用JOIN語(yǔ)句將多個(gè)表格進(jìn)行連接。這種方法相對(duì)于JSON數(shù)據(jù)類型更加靈活,但是需要進(jìn)行多次查詢和連接操作,適合于需要頻繁查詢的場(chǎng)景。