最新发布
今日更新156篇
文章总数10659篇
Mybatis like查询的写法–转载
原文地址：http://lavasoft.blog.51cto.com/62575/1386870Mybatis like查询官方文档没有明确的例子可循，网上搜索了很多，都不正确。Mybatis 3.2.6经过尝试，给出三种可靠可用的写法：select * from person where name like %#{name}%select * from person wh
mysql 获取自增id的值的方法
原生jdbc方式：Statement.getGeneratedKeys()示例：Statement stmt = null;ResultSet rs = null;try {//// Create a Statement instance that we can use for// normal result sets assuming you have a// Connection conn to a MySQL database already// ava
mysql 表的timestamp为自动添加
新设计表时可以执行语句：`update_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 更新时间,修改表可执行语句：ALTER TABLE table_nameMODIFY COLUMN update_time TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON
Loading half a billion rows into MySQL—转载
BackgroundWe have a legacy system in our production environment that keeps track of when a user takes an action on Causes.com (joins a Cause, recruits a friend, etc). I say legacy, but I really mean a prematurely-optimized system that I’d
mysql Integer Types (Exact Value) – INTEGER, INT, SMALLINT,
使用mysql的时候，用到int类型的蛮多，需要注意一下：1. 值的范围TypeStorageMinimum ValueMaximum Value(Bytes)(Signed/Unsigned)(Signed/Unsigned)TINYINT1-128127255SMALLINT2-327683276765535MEDIUMINT3-8388608838860716777215INT4-21474836482147483647
mybatis中#{}和${}的区别
mybatis本身的说明：String SubstitutionBy default, using the #{} syntax will cause MyBatis to generate PreparedStatement properties and set the values safely against the PreparedStatement parameters (e.g. ?). While this is safer, faster and