mysql 新增字段

新建字段
alter table album_album add `cover` varchar(255) DEFAULT NULL;

mysql> alter table message_unreadcount add `gmt_updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP;
Query OK, 396280 rows affected (5.52 sec)

新建索引
alter table message_unreadcount add KEY `idx_mu_gmt_up` (`gmt_updated`);

删除索引
alter table table_name drop index index_name ;

发现有''有问题，去掉之后问题解决。

mysql> alter table search_needtoindex add index 'idx_needix_oid'('oid');
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''idx_needix_oid'('oid')' at line 1
mysql>
mysql>
mysql>
mysql>
mysql> alter table search_needtoindex add index idx_needix_oid (oid);
Query OK, 0 rows affected (0.06 sec)
Records: 0 Duplicates: 0 Warnings: 0