05 mybatis的动态sql操作

mybatis的动态SQL操作

实现步骤
1、项目搭建（maven配置）
2、数据库创建
3、java实体创建
4、mapper文件创建
5、配置文件创建
6、测试：数据操作

一、项目配置

1.1、maven配置

<dependencies>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.45</version>
        </dependency>

        <!--基础包-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.7</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.0</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.0</version>
        </dependency>
    </dependencies>

1.2、数据库表创建

create table mybatis_dynamic(
  dynamic_id int(3) auto_increment not null primary key,
  dynamic_name varchar(200),
  dynamic_title varchar(200),
  dynamic_desc varchar(200)
)

1.3、java实体创建

get，set方法省略

public class DynamicObject {
    private Integer dynamicId;
    private String dynamicName;
    private String dynamicTitle;
    private String dynamicDesc;
}

1.4、配置文件创建

<?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>

    <typeAliases>
        <typeAlias type="com.demo.mybatis.DynamicObject" alias="DynamicObject"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url"
                          value="jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&amp;characterEncoding=UTF-8"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="mapper/DynamicMapper.xml"/>
    </mappers>
</configuration>

1.5、创建获取SqlSession方法

    public SqlSession getSession() {
        SqlSession session = null;
        try {
            Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
            SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader);
            return factory.openSession();
        } catch (IOException e) {
            e.printStackTrace();
            session.rollback();
            return null;
        }
    }

1.6、mapper配置文件映射配置

<mapper namespace="DynamicMapper">

    <resultMap id="dynamicResult" type="DynamicObject">
        <id property="dynamicId" column="dynamic_id"/>
        <result property="dynamicName" column="dynamic_name"/>
        <result property="dynamicTitle" column="dynamic_title"/>
        <result property="dynamicDesc" column="dynamic_desc"/>
    </resultMap>

二、具体操作

2.1、数据插入

2.1.1、mapper配置

    <insert id="insertDynamic" parameterType="DynamicObject">
        insert mybatis_dynamic (dynamic_name,dynamic_title,dynamic_desc)
        values (#{dynamicName},#{dynamicTitle},#{dynamicDesc})
    </insert>

2.1.2、代码操作

    @Test
    public void insert() {
        SqlSession session = getSession();
        DynamicObject object = new DynamicObject();
        object.setDynamicDesc("insert desc from insert method");
        object.setDynamicName("insert name from insert method");
        object.setDynamicTitle("insert title from insert method");
        session.insert("DynamicMapper.insertDynamic", object);
        session.commit();
    }

2.1.3、执行的sql语句

Preparing: insert mybatis_dynamic (dynamic_name,dynamic_title,dynamic_desc) values (?,?,?) 
Parameters: insert name from insert method(String), insert title from insert method(String), insert desc from insert method(String)
Updates: 1

2.2、数据模糊查询

有三种方式：使用if，where，choose标签

2.2.1、mapper配置

<select id="selectByLike" parameterType="DynamicObject" resultMap="dynamicResult">
        select * from mybatis_dynamic where 1=1
        <if test="dynamicName != null"> and dynamic_name = #{dynamicName}</if>
        <if test="dynamicTitle != null"> and dynamic_title = #{dynamicTitle}</if>
        <if test="dynamicDesc != null"> and dynamic_desc = #{dynamicDesc}</if>

    </select>

    <select id="selectByWhere" parameterType="DynamicObject" resultMap="dynamicResult">
         select * from mybatis_dynamic
         <where>
             <if test="dynamicName != null"> and dynamic_name = #{dynamicName}</if>
             <if test="dynamicTitle != null"> and dynamic_title = #{dynamicTitle}</if>
             <if test="dynamicDesc != null"> and dynamic_desc = #{dynamicDesc}</if>
         </where>
    </select>

    <select id="selectByChoose" parameterType="DynamicObject" resultMap="dynamicResult">
         select * from mybatis_dynamic
         <where>
             <choose>
                 <when test="dynamicName != null"> and dynamic_name = #{dynamicName}</when>
                 <when test="dynamicTitle != null"> and dynamic_title = #{dynamicTitle}</when>
                 <when test="dynamicDesc != null"> and dynamic_desc = #{dynamicDesc}</when>
                 <otherwise>and 1==2</otherwise>
             </choose>
         </where>
    </select>

2.2.2、代码操作

    @Test
       public void selectByLike() {
           SqlSession session = getSession();
           DynamicObject object = new DynamicObject();
           object.setDynamicName("insert name from insert method");
           object.setDynamicTitle("insert title from insert method");
           List<DynamicObject> select = session.selectList("DynamicMapper.selectByLike", object);
           System.out.println(select.toString());
           session.commit();
       }


       @Test
       public void selectByWhere() {
           SqlSession session = getSession();
           DynamicObject object = new DynamicObject();
           object.setDynamicName("insert name from insert method");
           List<DynamicObject> select = session.selectList("DynamicMapper.selectByWhere", object);
           System.out.println(select.toString());
           session.commit();
       }

       @Test
       public void selectByChoose() {
           SqlSession session = getSession();
           DynamicObject object = new DynamicObject();
           object.setDynamicName("insert name from insert method");
           List<DynamicObject> select = session.selectList("DynamicMapper.selectByChoose", object);
           System.out.println(select.toString());
           session.commit();
       }

2.2.3、执行的sql

//selectByLike
select * from mybatis_dynamic where 1=1 and dynamic_name = ? and dynamic_title = ? 
Parameters: insert name from insert method(String), insert title from insert method(String)
Total: 5

//selectByWhere
Preparing: select * from mybatis_dynamic WHERE dynamic_name = ? 
Parameters: insert name from insert method(String)
Total: 5

//selectByChoose
 Preparing: select * from mybatis_dynamic WHERE dynamic_name = ? 
 Parameters: insert name from insert method(String)
 Total: 5

2.2.4、说明：

where标签只选取有值的字段，choose只选取一个有值的字段

2.3、set标签

采用set标签，只更新有值的数据

2.3.1、mapper配置

    <update id="updateSet" parameterType="DynamicObject">
        update mybatis_dynamic
      <set>
          <if test="dynamicName != null">dynamic_name = #{dynamicName},</if>
          <if test="dynamicTitle != null">dynamic_title = #{dynamicTitle},</if>
          <if test="dynamicDesc != null">dynamic_desc = #{dynamicDesc}</if>
      </set>
        where dynamic_id =#{dynamicId}
    </update>

2.3.2、测试

    @Test
    public void updateSet() {
        SqlSession session = getSession();
        DynamicObject object = new DynamicObject();
        object.setDynamicId(3);
        object.setDynamicName("update set name");
        session.update("DynamicMapper.updateSet", object);
        session.commit();
    }

2.3.3、执行sql语句

 Preparing: update mybatis_dynamic SET dynamic_name = ? where dynamic_id =? 
 Parameters: update set name(String), 3(Integer)
 Updates: 1

2.4、foreach标签

采用循环获取数据

2.4.1、mapper配置

    <select id="selectForeach" resultMap="dynamicResult">
        select * from mybatis_dynamic where dynamic_id in
        <foreach collection="list" item="dynamicId" separator="," open="(" close=")">
            #{dynamicId}
        </foreach>
    </select>

2.4.2、测试：

    @Test
    public void selectForeach() {
        List<Integer> list = new ArrayList<Integer>();
        list.add(3);
        list.add(5);
        list.add(6);

        SqlSession session = getSession();
        List<DynamicObject> objectList = session.selectList("DynamicMapper.selectForeach", list);
        System.out.println(objectList.toString());
    }

2.4.3、执行后sql

Preparing: select * from mybatis_dynamic where dynamic_id in ( ? , ? , ? ) 
Parameters: 3(Integer), 5(Integer), 6(Integer)
Total: 3

2.5、include标签

引用其他sql

2.5.1、mapper配置

    <insert id="includeInsert" parameterType="DynamicObject">
        insert into mybatis_dynamic
        <include refid="key"/>
        values
        <include refid="value"/>
    </insert>

    <sql id="key">
        <trim suffixOverrides="," prefix="(" suffix=")">
            <if test="dynamicName != null">dynamic_name,</if>
            <if test="dynamicTitle != null">dynamic_title,</if>
            <if test="dynamicDesc != null">dynamic_desc</if>
        </trim>
    </sql>

    <sql id="value">
        <trim suffixOverrides="," prefix="(" suffix=")">
            <if test="dynamicName != null">#{dynamicName},</if>
            <if test="dynamicTitle != null">#{dynamicTitle},</if>
            <if test="dynamicDesc != null">#{dynamicDesc}</if>
        </trim>
    </sql>

2.5.2、测试

    @Test
    public void includeInsert(){
        SqlSession session = getSession();
        DynamicObject object = new DynamicObject();
        object.setDynamicName("insert  name by include");
        object.setDynamicTitle("insert  title by include");
        session.update("DynamicMapper.includeInsert", object);
        session.commit();
    }

2.5.3、执行后sql：

Preparing: insert into mybatis_dynamic ( dynamic_name, dynamic_title ) values ( ?, ? ) 
Parameters: insert  name by include(String), insert  title by include(String)
Updates: 1

代码

https://github.com/brusion/brusion-code/tree/master/demo-java/04%20-%20demo%20-%20mybatis/mybatis-03

05 mybatis的动态sql操作

mybatis的动态SQL操作

一、项目配置

1.1、maven配置

1.2、数据库表创建

1.3、java实体创建

1.4、配置文件创建

1.5、创建获取SqlSession方法

1.6、mapper配置文件映射配置

二、具体操作

2.1、数据插入

2.1.1、mapper配置

2.1.2、代码操作

2.1.3、执行的sql语句

2.2、数据模糊查询

2.2.1、mapper配置

2.2.2、代码操作

2.2.3、执行的sql

2.2.4、说明：

2.3、set标签

2.3.1、mapper配置

2.3.2、测试

2.3.3、执行sql语句

2.4、foreach标签

2.4.1、mapper配置

2.4.2、测试：

2.4.3、执行后sql

2.5、include标签

2.5.1、mapper配置

2.5.2、测试

2.5.3、执行后sql：

代码

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