动态SQL代码
|
175
|
0
|
MyBatis Code

464 字
|
23 分钟

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>top.qaqaq.mybatis</groupId>
  <artifactId>MyBatis_demo3</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>MyBatis_demo3</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

    <!-- Mybatis核心 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.7</version>
    </dependency>
    <!-- junit测试 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <!-- MySQL驱动 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.31</version>
    </dependency>
    <!-- log4j日志 -->
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>

  </dependencies>
</project>

resources

mybatis-config.xml

<?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>

    <properties resource="jdbc.properties"/>

    <!--设置MyBatis的全局配置-->
    <settings>
        <!--将_自动映射为驼峰，emp_name:empName-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!--开启延迟加载-->
        <setting name="lazyLoadingEnabled" value="true"/>
    </settings>

    <typeAliases>
        <package name="top.qaqaq.mybatis.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <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>

    <mappers>
        <package name="top.qaqaq.mybatis.mapper"/>
    </mappers>
</configuration>

jdbc.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis
jdbc.username=root
jdbc.password=123456

log4j.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Encoding" value="UTF-8" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS}%m (%F:%L) \n" />
        </layout>
    </appender>
    <logger name="java.sql">
        <level value="debug" />
    </logger>
    <logger name="org.apache.ibatis">
        <level value="info" />
    </logger>
    <root>
        <level value="debug" />
        <appender-ref ref="STDOUT" />
    </root>
</log4j:configuration>

resources/mapper

DynamicSQLMapper.xml

<?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="top.qaqaq.mybatis.mapper.DynamicSQLMapper">

    <!--int insertMoreByList(List<Emp> emps);-->
    <insert id="insertMoreByList">
        insert into t_emp values
        <foreach collection="emps" item="emp" separator=",">
            (null,#{emp.empName},#{emp.age},#{emp.sex},#{emp.email},null)
        </foreach>
    </insert>
    
    <!--int deleteMoreByArray(@Param("eids") Integer[] eids);-->
    <delete id="deleteMoreByArray">
        delete from t_emp where
        <foreach collection="eids" item="eid" separator="or">
            eid = #{eid}
        </foreach>
    </delete>

    <delete id="deleteMoreByArrayOne">
        delete from t_emp where eid in
        <foreach collection="eids" item="eid" separator="," open="(" close=")">
            #{eid}
        </foreach>
    </delete>

    <!--List<Emp> getEmpByChoose(Emp emp);-->
    <select id="getEmpByChoose" resultType="Emp">
        select * from t_emp
        <where>
            <choose>
                <when test="empName != null and empName != ''">
                    emp_name = #{empName}
                </when>
                <when test="age != null and age != ''">
                    age = #{age}
                </when>
                <when test="sex != null and sex != ''">
                    sex = #{sex}
                </when>
                <when test="email != null and email != ''">
                    email = #{email}
                </when>
                <otherwise>
                    did = 1
                </otherwise>
            </choose>
        </where>
    </select>

    <sql id="empColumns">eid,emp_name,age,sex,email</sql>

    <!--List<Emp> getEmpByCondition(Emp emp);-->
    <select id="getEmpByCondition" resultType="Emp">
        select <include refid="empColumns"></include> from t_emp
        <trim prefix="where" suffixOverrides="and|or">
            <if test="empName != null and empName != ''">
                emp_name = #{empName} and
            </if>
            <if test="age != null and age != ''">
                age = #{age} or
            </if>
            <if test="sex != null and sex != ''">
                sex = #{sex} and
            </if>
            <if test="email != null and email != ''">
                email = #{email}
            </if>
        </trim>

    </select>

    <select id="getEmpByConditionTwo" resultType="Emp">
        select * from t_emp
        <where>
            <if test="empName != null and empName != ''">
                emp_name = #{empName}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
            <if test="sex != null and sex != ''">
                or sex = #{sex}
            </if>
            <if test="email != null and email != ''">
                and email = #{email}
            </if>
        </where>

    </select>

    <select id="getEmpByConditionOne" resultType="Emp">
        select * from t_emp where 1=1
        <if test="empName != null and empName != ''">
            emp_name = #{empName}
        </if>
        <if test="age != null and age != ''">
            and age = #{age}
        </if>
        <if test="sex != null and sex != ''">
            and sex = #{sex}
        </if>
        <if test="email != null and email != ''">
            and email = #{email}
        </if>
    </select>

</mapper>

mapper

DynamicSQLMapper .java

package top.qaqaq.mybatis.mapper;

import org.apache.ibatis.annotations.Param;
import top.qaqaq.mybatis.pojo.Emp;

import java.util.List;

public interface DynamicSQLMapper {

    /**
     * 多条件查询
     */
    List<Emp> getEmpByCondition(Emp emp);

    /**
     * 测试choose、when、otherwise
     */
    List<Emp> getEmpByChoose(Emp emp);

    /**
     * 通过数组实现批量删除
     */
    int deleteMoreByArray(@Param("eids") Integer[] eids);

    /**
     * 通过list集合实现批量添加
     */
    int insertMoreByList(@Param("emps") List<Emp> emps);
}

pojo

Emp .java

package top.qaqaq.mybatis.pojo;

public class Emp {

    private Integer eid;
    private String empName;
    private Integer age;
    private String sex;
    private String email;
    private Dept dept;

    public Emp() {
    }

    public Emp(Integer eid, String empName, Integer age, String sex, String email) {
        this.eid = eid;
        this.empName = empName;
        this.age = age;
        this.sex = sex;
        this.email = email;
    }

    public Integer getEid() {
        return eid;
    }

    public void setEid(Integer eid) {
        this.eid = eid;
    }

    public String getEmpName() {
        return empName;
    }

    public void setEmpName(String empName) {
        this.empName = empName;
    }

    public Integer getAge() {
        return age;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Dept getDept() {
        return dept;
    }

    public void setDept(Dept dept) {
        this.dept = dept;
    }

    @Override
    public String toString() {
        return "Emp{" +
                "eid=" + eid +
                ", empName='" + empName + '\'' +
                ", age=" + age +
                ", sex='" + sex + '\'' +
                ", email='" + email + '\'' +
                ", dept=" + dept +
                '}';
    }

}

utils

SqlSessionUtils .java

package top.qaqaq.mybatis.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class SqlSessionUtils {

    public static SqlSession getSqlSession() {
        SqlSession sqlSession = null;
        try {
            InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
            sqlSession = sqlSessionFactory.openSession(true);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return sqlSession;
    }
}

test

DynamicSQLMapperTest .java

package top.qaqaq.mybatis.test;

import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import top.qaqaq.mybatis.mapper.DynamicSQLMapper;
import top.qaqaq.mybatis.pojo.Emp;
import top.qaqaq.mybatis.utils.SqlSessionUtils;

import java.util.Arrays;
import java.util.List;

public class DynamicSQLMapperTest {

    /**
     * 动态SQL：
     * 1、if：根据标签中test属性所对应的表达式决定标签中的内容是否需要拼接到SQL中
     * 2、where：
     * 当where标签中有内容时，会自动生成where关键字，并且将内容前多余的and 或 or 去掉
     * 当where标签中没有内容时，此时where标签没有任何效果
     * 注意：where标签不能将其中内容后面多余的 and 或 or 去掉
     * 3、trim：
     * 若标签中有内容时：
     * prefix|suffix：将trim标签中内容前面或后面添加指定内容
     * prefixOverrides|suffixOverrides：将trim标签中内容前面或后面去掉指定内容
     * 若标签中没有内容时，trim标签也没有任何效果
     * 4、choose、when、otherwise，相当于if...else if...else
     * when至少要有一个，otherwise最多只能有一个
     * 5、foreach
     * collection：设置需要循环的数组或集合
     * item：表示数组或集合中的每一个数据
     * separator：循环体之间的分割符
     * open：foreach标签所循环的所有内容的开始符
     * close：foreach标签所循环的所有内容的结束符
     * 6、sql标签
     * 设置SQL片段：<sql id="empColumns">eid,emp_name,age,sex,email</sql>
     * 引用SQL片段：<include refid="empColumns"></include>
     */

    @Test
    public void testInsertMoreByList() {
        SqlSession sqlSession = SqlSessionUtils.getSqlSession();
        DynamicSQLMapper mapper = sqlSession.getMapper(DynamicSQLMapper.class);
        Emp emp1 = new Emp(null, "a1", 23, "男", "123@qq.com");
        Emp emp2 = new Emp(null, "a2", 23, "男", "123@qq.com");
        Emp emp3 = new Emp(null, "a3", 23, "男", "123@qq.com");
        List<Emp> emps = Arrays.asList(emp1, emp2, emp3);
        System.out.println(mapper.insertMoreByList(emps));
    }

    @Test
    public void testDeleteMoreByArray() {
        SqlSession sqlSession = SqlSessionUtils.getSqlSession();
        DynamicSQLMapper mapper = sqlSession.getMapper(DynamicSQLMapper.class);
        int result = mapper.deleteMoreByArray(new Integer[]{6, 7, 8});
        System.out.println(result);
    }

    @Test
    public void testGetEmpByChoose() {
        SqlSession sqlSession = SqlSessionUtils.getSqlSession();
        DynamicSQLMapper mapper = sqlSession.getMapper(DynamicSQLMapper.class);
        List<Emp> list = mapper.getEmpByChoose(new Emp(null, "", null, "", ""));
        System.out.println(list);
    }

    @Test
    public void testGetEmpByCondition() {
        SqlSession sqlSession = SqlSessionUtils.getSqlSession();
        DynamicSQLMapper mapper = sqlSession.getMapper(DynamicSQLMapper.class);
        List<Emp> list = mapper.getEmpByCondition(new Emp(null, "", null, "", null));
        System.out.println(list);
    }
}
MyBatis
暂无评论

发送评论 编辑评论 


				

			

						

				

					

						

							

								
							

							
						

					

				

				

					

						

							

								
							

							
						

					

				

				

					

						

							

								
							

							
							
													

					

				

			

			
			

				

					
				

			

				

											

							
							
						

																				
					
											
						

	

		
|´・ω・)ノ
ヾ(≧∇≦*)ゝ
(☆ω☆)
（╯‵□′）╯︵┴─┴
￣﹃￣
(/ω＼)
∠( ᐛ 」∠)＿
(๑•̀ㅁ•́ฅ)
→_→
୧(๑•̀⌄•́๑)૭
٩(ˊᗜˋ*)و
(ノ°ο°)ノ
(´இ皿இ｀)
⌇●﹏●⌇
(ฅ´ω`ฅ)
(╯°A°)╯︵○○○
φ(￣∇￣o)
ヾ(´･ ･｀｡)ノ"
( ง ᵒ̌皿ᵒ̌)ง⁼³₌₃
(ó﹏ò｡)
Σ(っ °Д °;)っ
( ,,´･ω･)ﾉ"(´っω･｀｡)
╮(╯▽╰)╭
o(*////▽////*)q
＞﹏＜
( ๑´•ω•) "(ㆆᴗㆆ)
😂
😀
😅
😊
🙂
🙃
😌
😍
😘
😜
😝
😏
😒
🙄
😳
😡
😔
😫
😱
😭
💩
👻
🙌
🖕
👍
👫
👬
👭
🌚
🌝
🙈
💊
😶
🙏
🍦
🍉
😣
Source: github.com/k4yt3x/flowerhd
	

	

		
颜文字
Emoji
小恐龙
花!
	


									

			

			
			
		

	






上一篇
下一篇 

                    

                    
			        推荐文章
		            

		            

							
分页插件代码

							
							

							
分页插件

							
							

							
MyBatis的逆向工程代码

							
							

							
MyBatis的逆向工程

							
							

							
MyBatis的缓存代码

							
							

							
MyBatis的缓存