mysql 数据用逗号分隔

SELECT * FROM table_name WHERE FIND_IN_SET('tag_to_search', tags);

-- 假设我们有一个表 `articles`，其中 `tags` 字段存储了逗号分隔的标签
CREATE TABLE articles (
    id INT PRIMARY KEY,
    title VARCHAR(255),
    tags VARCHAR(255)
);

-- 插入一些数据
INSERT INTO articles (id, title, tags) VALUES
(1, 'Article 1', 'tag1,tag2,tag3'),
(2, 'Article 2', 'tag2,tag4'),
(3, 'Article 3', 'tag1,tag3,tag5');

-- 查询包含 'tag2' 的文章
SELECT * FROM articles WHERE FIND_IN_SET('tag2', tags);

-- 假设我们有一个表 `articles`，其中 `tags` 字段存储了逗号分隔的标签
-- 查询并按标签排序
SELECT * FROM articles ORDER BY FIELD(FIND_IN_SET('tag1', tags), FIND_IN_SET('tag2', tags), FIND_IN_SET('tag3', tags));

-- 拆分逗号分隔的字符串并分组
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(tags, ',', numbers.n), ',', -1) AS tag, COUNT(*) AS count
FROM articles
JOIN (
    SELECT 1 n UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
    UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10
) numbers ON CHAR_LENGTH(tags) - CHAR_LENGTH(REPLACE(tags, ',', '')) >= numbers.n - 1
GROUP BY tag;