MySQL common operations (regular expression) ---DAY_6

-- regular expression
-- REGEXP



-- ^ 匹配字符开始的部分

SELECT * FROM cms_user 
WHERE username REGEXP '^k';




-- $ 匹配结尾部分

SELECT * FROM cms_user 
WHERE username REGEXP 'g$';




-- . 代表任意一个字符，包括回车与换行

SELECT * FROM cms_user 
WHERE username REGEXP 'kin.';


SELECT * FROM cms_user 
WHERE username REGEXP 'kin.';
-- similar like __
SELECT * FROM cms_user 
WHERE username like 'k___';

-- [字符集]，匹配字符集中任何一个字符


SELECT * FROM cms_user 
WHERE username REGEXP '[ltog]';

SELECT * FROM cms_user 
WHERE username REGEXP '[a-k]';


-- [^字符集合]匹配除了字符集以外的任何一个字符

SELECT * FROM cms_user 
WHERE username REGEXP '[^ltog]';

SELECT * FROM cms_user 
WHERE username REGEXP '[^a-k]';

-- S1|S2|S3 匹配S1,S2,S3中任意一个字符

SELECT * FROM cms_user 
WHERE username REGEXP 'in|ng';


-- *代表0个1个或多个其前的字符串

SELECT * FROM cms_user 
WHERE username REGEXP 'que*';


-- + 代表1个或多个其前的字符串

SELECT * FROM cms_user 
WHERE username REGEXP 't+';
SELECT * FROM cms_user 
WHERE username REGEXP 'que+';



-- STRING(N)字符出现N次


SELECT * FROM cms_user 
WHERE username REGEXP 'que{2}';




-- 字符串(M,N)至少出现M次，最多N次

SELECT * FROM cms_user 
WHERE username REGEXP 'ue{1,3}';