Mysql 问题集

-- [1]删除表
DROP TABLE tbl_name;
-- [2]创建表
CREATE TABLE tbl_name (ID INT, mSize VARCHAR(100));
INSERT INTO tbl_name VALUES
(1, 'tiny,small,big'),
(2, 'small,medium'),
(3, 'tiny,big');
-- [3]创建表
SELECT * FROM tbl_name;

SELECT a.ID, SUBSTRING_INDEX(SUBSTRING_INDEX(a.mSize, ',', b.help_topic_id+1), ',', -1) AS VALUE
FROM tbl_name a 
JOIN mysql.help_topic b 
ON b.help_topic_id < (LENGTH(a.mSize) - LENGTH(REPLACE(a.mSize, ',', '')) + 1)
ORDER BY a.ID;