SQL随笔

多表分页查询：

select p.* from category c ,categorysecond cs , product p where c.cid = cs.cid and cs.csid = p.csid and c.cid = 2 order by pdate desc limit 0,2;

 

向表中插入新的字段：

ALTER TABLE `Table_name`
ADD COLUMN `Column_name` VARCHAR(15) NOT NULL DEFAULT '' AFTER `id`;

 

 更新表数据：

UPDATE [LOW_PRIORITY] [IGNORE] table_name
SET col_name1=expr1 [, col_name2=expr2 ...]
[WHERE where_definition]

 

查询所有的表信息：

select * from sysibm.systables AS s where type = 'T' and creator = 'DB2USER' ORDER BY s.NAME

 

复制数据库：

mysqldump olddb -u root -p**** --add-drop-table | mysql newdb -u root -p****

 复制数据库至远程：

mysqldump olddb -uroot -p**** --add-drop-table | mysql -h 192.168.1.22 newdb -u root -p****