Question

如何用MYSQL函数删除字符串最后几个字符？

Answer 1

先把自动事务提交关掉, 或者做好备份工作.
SET AUTOCOMMIT = 0;

删除最后5个字符:
UPDATE NEWS
SET NEWSTEXT = substring(NEWSTEXT,1,length(NEWSTEXT)-5)
WHERE ID BETWEEN 100 AND 200
AND length(NEWSTEXT) > 5;

删除最后一个字符为 `,`:
UPDATE NEWS
SET NEWSTEXT =
CASE WHEN NEWSTEXT LIKE '%,' THEN substring(NEWSTEXT,1,length(NEWSTEXT)-1)
ELSE NEWSTEXT END
WHERE ID BETWEEN 100 AND 200
AND NEWSTEXT LIKE '%,';

大意是这样, 细节再调整下, 执行完查下数据是否正确再提交.