MyBatis基础

Posted 2020-10-03 MyBatis

一.大配置

<?xml version="1.0" encoding="UTF-8" ?>
<!--文档类型，头文件-->
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--根节点，XMl只能有一个-->
<configuration>
    <!--一个environments有N个environment-->
    <typeAliases>
        <package name="cn.bdqn.entity"></package>
    </typeAliases>
    <environments default="development">

        <environment id="development">
            <!--
           transactionManager:JDBC保证事务的
           update
           delete
           事务分类：JDBC:编程式事务
                       xxx.beginTransaction()

                       tx.commit()
                       tx.rollback()
                     配置式事务
                     JDBC|MANAGED
                     区别

           -->
            <transactionManager type="JDBC"></transactionManager>
            <!--
               POOLED：MyBatis内置的连接池
               c3p0连接池
                       POOLED 、UNPOOLED  、JNDI
           -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///blog"/>
                <property name="username" value="root"/>
                <property name="password" value="1234"/>
            </dataSource>

        </environment>
    </environments>

<mappers>
<mapper resource="cn/bdqn/dao/DeptMappr.xml"></mapper>
        </mappers>
        </configuration>

 

二.小配置

<?xml version="1.0" encoding="UTF-8"?>
<!--头文件-->
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace：
     命名空间：区分不同空间下的同名SQLID
     A： findlAll
     B:  findAll
    -->
<mapper namespace="cn.bdqn.dao.IDeptDao">
    <!--SQL标签
      id:唯一锁定到SQL标识
      paramenterType:SQL语句的入参  可以省略
      resultType：
      增删除操作：不能 写
      查询：单个实体的类型
    -->
    <select id="getAll"  resultType="Dept">
  /*SQL文：SQL语句*/
    SELECT * FROM  bloginfo
    </select>
    <select id="getid"  resultType="Dept">
        /*SQL文：SQL语句*/
        SELECT * FROM  bloginfo WHERE blogId=#{blogId}
    </select>
</mapper>

三.jar包

 

   <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.2.2</version>
        </dependency>


        <!--mysql  jar包-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>

 

四.实体类

     public class StudentInfo {

     private Integer stuId;

     private String stuName;

     private Integer  stuAge;

     private Date stuDate;

}

五.更新POM.xml文件中build节点

 <build>

    <resources>

      <resource>

        <directory>src/main/java</directory>

        <includes>

          <include>**/*.xml</include>

        </includes>

      </resource>

    </resources>

  </build>

 

六.测试类 

InputStream is=Resources.getResourcesAsStream(path);

SessionFactory factory=new SessionFactoryBuilder().build(is);

SqlSession session=factory.openSession();

<?xml version="1.0" encoding="UTF-8" ?>

<!--文档类型，头文件-->
<!DOCTYPEconfiguration
PUBLIC"-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--根节点，XMl只能有一个-->
<configuration>
    <!--一个environments有N个environment-->
<typeAliases>
        <package name="cn.bdqn.entity"></package>
    </typeAliases>
    <environments default="development">

        <environment id="development">
            <!--
           transactionManager:JDBC保证事务的
           update
           delete
           事务分类：JDBC:编程式事务
                       xxx.beginTransaction()

                       tx.commit()
                       tx.rollback()
                     配置式事务
                     JDBC|MANAGED
                     区别

           -->
<transactionManager type="JDBC"></transactionManager>
            <!--
               POOLED：MyBatis内置的连接池
               c3p0连接池
                       POOLED 、UNPOOLED  、JNDI
           -->
<dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///blog"/>
                <property name="username" value="root"/>
                <property name="password" value="1234"/>
            </dataSource>

        </environment>
    </environments>

<mappers>
<mapper resource="cn/bdqn/dao/DeptMappr.xml"></mapper>
        </mappers>
        </configuration>