show status like '%handler_read_key%'; #走索引的命令的数量. #查看存储引擎 mysql> show variables like '%engine%';+----------------------------+--------+| Variable_name | Value |+----------------------------+--------+| default_storage_engine | InnoD
用法 mysql>show table status; mysql>show table status like 'esf_seller_history'\G; mysql>show table status like 'esf_%'\G; 例子: mysql>show table status like 'esf_seller_history'\G; 1.Name 表名称 2.Engine: 表的存储引擎 3.Version: 版本号
================START============================== 来了一个mail说是job跑得很慢,调查下原因 先来看下sql: SELECT h.order_no AS SO_no, h.order_type, h1.order_no AS po_no, l1.order_line_key AS PO_LKEY, l1.shipn
Mysql复制一条或多条记录并插入表|mysql从某表复制一条记录到另一张表 一.复制表里面的一条记录并插入表里面 ① insert into article(title,keywords,desc,contents) select title,keywords,desc,contents from article where article_id = 100; 二.复制表里的多条数据/记录,并插入到表里面 ① INSERT INTO `power_node`(title,type,
4张表:filter nat mangle raw filter:协议过滤: nat:地址转换,端口映射等: mangle:协议修改 TTL等: raw:This table is used mainly for configuring exemptions from connection tracking in combination with the NOTRACK target. It registers at the netfilter hooks with hig
1.在面试的时候碰到一个 问题,就是让写一张表中有id和name 两个字段,查询出name重复的所有数据,现在列下: select * from xi a where (a.username) in (select username from xi group by username having count(*) > 1) 2.查询出所有数据进行分组之后,和重复数据的重复次数的查询数据,先列下: select count(username) as '重复次数',username from
一,创建一个公共的DBAdapter; 为了在整个程序运行期间调用该公共的数据库,我们定义了一个扩展自Application的CommDB类: 1,创建唯一的数据库: public class CommDB { public static final String DATABASE_NAME = "myDatabase"; //数据库名称 public static final int DATABASE_VERSION = 1; //创建该数据库下学生表的语句 private stat