mybatis的配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="org.mariadb.jdbc.Driver"/> //mariadb的驱动
<property name="url" value="jdbc:mariadb://localhost:3306/mydb"/> // url
<property name="username" value="root"/> // 用户
<property name="password" value="admin"/> // 密码
<mapper resource="userMapper.xml"/> //需要读取的资源文件
</configuration>
//crud等标签操作
<mapper namespace="mapper"> //命名空间 读取是需要 namespace + id
<select id="selectUser" resultType="zhu.User">
select* from book
<select id="selectUserCount" resultType="int">
selectcount(1) from book
<select id="selectUsersByPage1" resultType="zhu.User">
select* from book limit 3,3
<select id="selectUsersByPage2" resultType="zhu.User">
select* from book limit #{pagesize}
<select id="selectUsersByPage3" resultType="zhu.User">
select* from book limit #{indexstart},#{pagesize}
<insert id="saveUser" >
insert into book values(null, #{userName}, #{password}, #{add});
<delete id="delete" >
delete from book where id=#{id};
<update id="updata">
update book set userName=#{userName},password=#{password} where id=8
</update>
#{ }：占位符号，可以防止sql注入（替换结果会增加单引号‘’）
${ }：sql拼接符号（替换结果不会增加单引号‘’，like和order by后使用，存在sql注入问题，需手动代码中过滤）
