mybatis动态sql

1、数据库表

CREATE TABLE `student` (
  `tid` int(5) NOT NULL AUTO_INCREMENT,
  `tage` int(11) DEFAULT NULL,
  `tname` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`tid`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8

2、实体类

/**
 *学生的实体类
 */
public class Student {
    private Integer id; // 学生编号
    private String name; // 姓名
    private Integer age; // 年龄

    /**
     * 对应的有参无参构造以及对应的get和set方法
     */
    public Student() {
        super();
    }

    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

    public Student(Integer id, String name, Integer age) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public Student(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

3、mybatis配置文件

<?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">
<configuration>

    <!-- 通过properties文件配置连接数据库的四要素 -->
    <properties resource="jdbc.properties" />
    
    
    <!-- 设置别名 两种方式 -->
    <typeAliases>
           <!--  01.这种方式别名可以随意取  但是如果有多个 类 就需要配置多个typeAlias 
           <typeAlias type="cn.bdqn.bean.Student" alias="student"/> -->
           <package name="cn.bdqn.bean"/><!-- 02.这种方式要求别名必须使用简写的类名  -->
    </typeAliases>
    
    
    <!-- 配置运行环境 可以有多个 environment -->
    <environments default="mysql"><!-- 默认采用的环境 -->
        <environment id="mysql"> <!-- 环境的名称 -->
            <!--配置事务管理 采用jdbc默认的事务管理 之后整合的时候 肯定是交给了 spring来处理了 -->
            <transactionManager type="JDBC" />
            <!-- 数据源采用的是连接池技术 POOLED:mybatis自带的数据源，JNDI:基于tomcat的数据源 -->
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    <!-- 加载映射文件信息 -->
    <mappers>
        <mapper resource="cn/bdqn/dao/StduentMapper.xml" />
    </mappers>
</configuration>

4、dao层

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Param;

import cn.bdqn.bean.Student;

public interface StudentDao {
    int addStudent(Student student);

    List<Student> selectAll();

    List<Student> selectStudentsByNameAndAge(Map<String, Object> map);

    List<Student> selectStudentsByNameAndAge1(@Param("name") String name,
            @Param("age") Integer age);

    List<Student> selectStudentsByNameAndAge2(String name, Integer age);

    int deleteStudentsByIds(@Param("ids") Integer[] ids);

    int deleteStudentsByIds1(@Param("ids") List<Integer> ids);

    int deleteStudentsByIds2(@Param("maps") Map<String, List<Integer>> maps);

    int deleteStudentsByIds3(
            @Param("maps") Map<String, Map<String, Integer>> maps);
}

5、Mapper文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-Mapper.dtd">
<mapper namespace="cn.bdqn.dao.StudentDao">
    <sql id="Base_Column_list">
        tid,tname,tage
    </sql>
    
    <resultMap type="student" id="BaseResultMap">
        <constructor>
         <idArg column="tid" jdbcType="INTEGER" javaType="java.lang.Integer" />
          <arg column="tname" jdbcType="VARCHAR" javaType="java.lang.String" />
          <arg column="tage" jdbcType="INTEGER" javaType="java.lang.Integer" />
        </constructor>
    </resultMap>
    
    <insert id="addStudent" parameterType="student">
        insert into
        student(tage,tname) values(#{age,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR})
        <!-- <selectKey keyProperty="tid" order="AFTER" resultType="int">
            SELECT LAST_INSERT_ID() as id
        </selectKey> -->
    </insert>
    <select id="selectAll" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_list"/>
        from student
    </select>
    
    <select id="selectStudentsByNameAndAge" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_list"/>
        from student
        <trim prefix="where" prefixOverrides="and | or">
            <if test="stu.name!=null">
                and tname like CONCAT('%',#{stu.name},'%')
            </if>
            <if test="age!=null">
                and tage > #{age}
            </if>
        </trim>
    </select>
    <select id="selectStudentsByNameAndAge1" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_list"/>
        from student
        <trim prefix="where" prefixOverrides="and | or">
            <if test="name!=null">
                and tname like CONCAT('%',#{name},'%')
            </if>
            <if test="age!=null">
                and tage > #{age}
            </if>
        </trim>
    </select>
    <select id="selectStudentsByNameAndAge2" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_list"/>
        from student
                where tname like CONCAT('%',#{0},'%')
                and tage > #{1}
    </select>
    
    <delete id="deleteStudentsByIds" parameterType="list">
        delete from student
        <if test="ids !=null and ids.length>0">
            where tid in
            <foreach collection="ids" index="index" item="item" open="(" separator="," close=")">
                #{item}
            </foreach>
        </if>
    </delete>
    <delete id="deleteStudentsByIds1" parameterType="list">
        delete from student
        <if test="ids !=null and ids.size()>0">
            where tid in
            <foreach collection="ids" index="index" item="item" open="(" separator="," close=")">
                #{item}
            </foreach>
        </if>
    </delete>
    <delete id="deleteStudentsByIds2" parameterType="list">
        <foreach collection="maps" index="key" item="ent" separator="union">
            delete from student
            where tid in
            <foreach collection="ent" index="index" item="item1" open="(" separator="," close=")">
                #{item1}
            </foreach>
        </foreach>
    </delete>
    
    <delete id="deleteStudentsByIds3" parameterType="map">
        <foreach collection="maps" index="key" item="ent" separator="union">
            delete from student
            where tid in
            <foreach collection="ent" index="index" item="item1" open="(" separator="," close=")">
                #{item1}
            </foreach>
        </foreach>
    </delete>
</mapper>

6、测试类

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.SqlSession;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Before;

import cn.bdqn.bean.Student;
import cn.bdqn.dao.StudentDao;
import cn.bdqn.util.MybatisUtil;

public class Test {
    private Logger logger = Logger.getLogger(Test.class);
    SqlSession session;
    StudentDao dao;

    @Before
    public void before() {
        // 因为需要关闭session 需要把session提取出去
        session = MybatisUtil.getSqlSession();
        dao = session.getMapper(StudentDao.class);
    }

    @After
    public void after() {
        if (session != null) {
            session.close();
        }
    }

    @org.junit.Test
    public void testAddStduent() {
        Student student = new Student();
        student.setAge(20);
        student.setName("dddd");
        dao.addStudent(student);
        session.commit();
    }

    @org.junit.Test
    public void selectStduents() {
        List<Student> students = dao.selectAll();
        for (Student student : students) {
            logger.debug("insert student.id=============>>>" + student);
        }
    }

    @org.junit.Test
    public void selectStduentsByNameAndAge() {
        Map<String, Object> map = new HashMap<String, Object>();
        Student student2 = new Student();
        student2.setName("小");
        map.put("stu", student2);
        map.put("age", 50);
        List<Student> students = dao.selectStudentsByNameAndAge(map);
        for (Student student : students) {
            logger.debug("insert student.id=============>>>" + student);
        }
    }

    @org.junit.Test
    public void selectStduentsByNameAndAge1() {
        List<Student> students = dao.selectStudentsByNameAndAge1(null, 50);
        for (Student student : students) {
            logger.debug("insert student.id=============>>>" + student);
        }
    }

    @org.junit.Test
    public void selectStduentsByNameAndAge2() {
        List<Student> students = dao.selectStudentsByNameAndAge1(null, 50);
        for (Student student : students) {
            logger.debug("insert student.id=============>>>" + student);
        }
    }

    @org.junit.Test
    public void selectStduentsByNameAndAge3() {
        List<Student> students = dao.selectStudentsByNameAndAge2("小", 50);
        for (Student student : students) {
            logger.debug("insert student.id=============>>>" + student);
        }
    }

    @org.junit.Test
    public void deleteStudents() {
        /*List<Integer> ids = new ArrayList<>();
        ids.add(1);
        ids.add(3);
        ids.add(4);*/
        int rowNum = dao.deleteStudentsByIds(new Integer[] { 1, 3, 4 });
        logger.debug("删除的行数======>" + rowNum);
        // session.commit();
    }

    @org.junit.Test
    public void deleteStudents1() {
        List<Integer> ids = new ArrayList<>();
        ids.add(1);
        ids.add(3);
        ids.add(4);
        int rowNum = dao.deleteStudentsByIds1(ids);
        logger.debug("删除的行数======>" + rowNum);
        // session.commit();
    }

    @org.junit.Test
    public void deleteStudents2() {
        Map<String, List<Integer>> maps = new HashMap<>();
        List<Integer> list = new ArrayList<>();
        list.add(1);
        list.add(3);
        list.add(4);
        maps.put("maps", list);
        int rowNum = dao.deleteStudentsByIds2(maps);
        logger.debug("删除的行数======>" + rowNum);
        // session.commit();
    }

    @org.junit.Test
    public void deleteStudents3() {
        Map<String, Map<String, Integer>> maps = new HashMap<>();
        Map<String, Integer> maps1 = new HashMap<>();
        maps1.put("1", 1);
        maps1.put("3", 3);
        maps1.put("4", 4);
        maps.put("maps", maps1);
        int rowNum = dao.deleteStudentsByIds3(maps);
        logger.debug("删除的行数======>" + rowNum);
        // session.commit();
    }
}