Mysql截取拼接字符串

1.截取字符串

select substring_index('1.5.1.1.2.', '.',-3);   --输出1.2.

2.截取字符串后再拼接字符串

SELECT CONCAT('0.',SUBSTRING_INDEX('1.5.1.1.2.','.',-4));  --输出0.1.1.2.

3.向menu表中插入复制的menu (mybatis语句)

INSERT INTO table_menu(projectid,id,level,fj,text,state,type)
SELECT #{projectid} AS projectid,id,level, CONCAT('0.',#{id},'.',substring_index(fj , '.', 1-`level`)),text,state,type FROM table_menu
WHERE fj LIKE #{fj} AND projectid=#{projectid}