左边
UPDATE fenlei_shipin SET type_name=LTRIM(type_name)
全部
UPDATE fenlei_shipin SET type_name=TRIM(type_name)
右边
UPDATE fenlei_shipin SET type_name=RTRIM(type_name)

更新截取数值
UPDATE book_info SET file_path = (SELECT SUBSTRING(file_path, 1, LENGTH(file_path)-4)) WHERE type =2 AND file_path LIKE ‘%.mp4%’

UPDATE book_info SET file_path = CONCAT(file_path,".pdf") WHERE id = 803

去除\r\n
查询\r\n
SELECT *FROM data_tree WHERE name LIKE ‘%\r\n%’;

去掉\r\n
UPDATE data_tree SET name = REPLACE( REPLACE( name , CHAR( 10 ) , ‘’ ) , CHAR( 13 ) , ‘’ )