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MyBatis的参数传递

seven_ • • 后端漫谈 • 阅读 287

导读：本篇文章讲解 MyBatis的参数传递，希望对大家有帮助，欢迎收藏，转发！站点地址：www.bmabk.com

MyBatis的参数传递

主要参考代码：

BookMapper:

package com.yzh7.mapper;

import com.yzh7.entity.Book;
import org.apache.ibatis.annotations.Param;

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


public interface BookMapper {
    //mybatis传参问题
    //1.传入一个参数:在mapper中可以用任意名字引用这个参数
    Book getById(Integer bookId);
    //2.传入多个基本类型参数:在mapper中无法通过参数名引用参数
    // 解决方法:1) 通过arg0,arg1... param1,param2...
    //        2) 通过@Param注解为方法参数设置参数mybatis能够引用的参数名
    Book getByNameAndAuthor(@Param("bn") String bookName,
                            @Param("at") String author);

    //3.传入对象:可以在mapper中直接应用对象属性
    Book getByMap(Map map);

    //4.传入对象:可以在mapper中直接应用对象属性
    Book getByBook(Book book);

    //5.区别#{},${}: 模糊查询
    // #{}:用参数占位的方式设置数据。不会有注入问题，但是不能用拼接方式拼接sql
    // ${}:直接用拼接sql的方式，拼接数据。有sql注入问题。一般用${value}引用单个参数值
    List<Book> listByBookName(String bookName);

    //查询
    List<Map> listAll();
    List<Book> listAll2();

    //添加
    int insert(Book book);
    //修改
    int update(Book book);
    //删除
    int delete(Integer bookId);
}

BookMapper.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="com.yzh7.mapper.BookMapper">
    <!--根据mapper接口中的方法定义增删改查-->
    <select id="listAll" resultType="map">
        select * from tb_book
    </select>
    <select id="listAll2" resultType="book">
        select * from tb_book
    </select>
    <select id="getById" parameterType="int" resultType="book">
        select * from tb_book
        where book_id = #{bookId}
    </select>

    <select id="getByNameAndAuthor" resultType="book">
        select * from tb_book
        where book_name=#{bn} and author=#{at}
    </select>


    <select id="getByMap" parameterType="map" resultType="book">
        select * from tb_book
        where book_name=#{bookName} and author=#{author}
    </select>

    <select id="getByBook" parameterType="book" resultType="book">
        select * from tb_book
        where book_name=#{bookName} and author=#{author}
    </select>

    <select id="listByBookName" resultType="book">
        select * from tb_book
        where book_name like '%${value}%'
    </select>



    <insert id="insert" parameterType="book">
        insert into tb_book
        (book_name,author,price,publisher,pub_date)
        values
        (#{bookName},#{author},#{price},#{publisher},#{pubDate})
    </insert>
</mapper>

demo2:

package com.yzh7.test;

import com.yzh7.entity.Book;
import com.yzh7.mapper.BookMapper;
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 org.junit.After;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author: hy
 * @create: 2022-08-15 10:33:45
 */
public class Demo2 {

    @Test
    public void test1() throws NoSuchMethodException {
        BookMapper bm = session.getMapper(BookMapper.class);
        //1.传入一个参数:在mybatis中可以用任意名字引用这个参数
        Book book = bm.getById(1);
        System.out.println(book);
    }

    @Test
    public void test2() throws NoSuchMethodException {
        BookMapper bm = session.getMapper(BookMapper.class);
        //2.传入多个基本类型参数:在mybatis中无法通过参数名引用参数
        //  正确引用方式： ary0,ary1....
        //              param1,param2
        Book book = bm.getByNameAndAuthor("图书1","作者1");
        System.out.println(book);
    }

    @Test
    public void test3() throws NoSuchMethodException {
        BookMapper bm = session.getMapper(BookMapper.class);
        //3.传入对象:可以在mapper中直接应用对象属性
        Map map = new HashMap();
        map.put("bookName","图书1");
        map.put("author","作者1");
        Book book =bm.getByMap(map);
        System.out.println(book);
    }

    @Test
    public void test4() throws NoSuchMethodException {
        BookMapper bm = session.getMapper(BookMapper.class);
        //4.传入对象:可以在mapper中直接应用对象属性
       Book b = new Book();
       b.setBookName("图书1");
       b.setAuthor("作者1");
        Book book =bm.getByBook(b);
        System.out.println(book);
    }

    @Test
    public void test5() throws NoSuchMethodException {
        BookMapper bm = session.getMapper(BookMapper.class);
        //5.区别#{},${}: 模糊查询
        // #{}:用参数占位的方式设置数据。不会有注入问题，但是不能用拼接方式拼接sql
        // ${}:直接用拼接sql的方式，拼接数据。有sql注入问题。一般用${value}引用单个参数值
        List<Book> bookList = bm.listByBookName("图");
        System.out.println(bookList);
    }

    //会话工厂
    private static SqlSessionFactory factory;
    //会话
    private SqlSession session;

    @BeforeClass
    public static void befCls() throws IOException {
        InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
        factory = new SqlSessionFactoryBuilder().build(is);
    }

    @Before
    public void bf(){
        session = factory.openSession();
    }

    @After
    public void af(){
        //提交事务
        session.commit();
        //关闭会话
        session.close();
    }
}

运行结果展示：

数据库/数据表：

在这里插入图片描述

Book getById(Integer bookId);

//1.传入一个参数:在mybatis中可以用任意名字引用这个参数
在这里插入图片描述

Book getByNameAndAuthor(@Param(“bn”) String bookName,@Param(“at”) String author);

//2.传入多个基本类型参数:在mybatis中无法通过参数名引用参数
// 正确引用方式： ary0,ary1…
// param1,param2
在这里插入图片描述

Book getByMap(Map map);

//3.传入对象:可以在mapper中直接应用对象属性
在这里插入图片描述

Book getByBook(Book book);

//4.传入对象:可以在mapper中直接应用对象属性
在这里插入图片描述

List listByBookName(String bookName);

//5.区别#{},${}: 模糊查询
// #{}:用参数占位的方式设置数据。不会有注入问题，但是不能用拼接方式拼接sql
//

:

直接用拼接

s

q

l

的方式，拼接数据。有

s

q

l

注入问题。一般用

{}:直接用拼接sql的方式，拼接数据。有sql注入问题。一般用

:直接用拼接sql的方式，拼接数据。有sql注入问题。一般用{value}引用单个参数值
在这里插入图片描述

项目实现思路（参考）：

在这里插入图片描述

代码整体布局：

在这里插入图片描述
注意：
在这里插入图片描述

完整代码：

数据库/数据表：

create table tb_book
(
	book_id int primary key auto_increment,
	book_name varchar(20),
	author varchar(20),
	price decimal(5,1),
	publisher varchar(20),
	pub_date date
);

select * from tb_book;

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<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>org.example</groupId>
    <artifactId>mybatis_0815_KTLX</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <!--引入jar包-->
    <dependencies>
        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>

        <!-- mysql驱动类 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

</project>

db.properties:

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/70813_db?useSSL=false&serverTimezone=Asia/Shanghai&characterEncoding=utf8&allowPublicKeyRetrieval=true
jdbc.username=root
jdbc.password=123456

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="db.properties"></properties>
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    <typeAliases>
        <package name="com.yzh7.entity"/>
    </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>
        <!--定义关联的mapper接口，通过三一致的规则自动与mapper文件关联-->
        <mapper class="com.yzh7.mapper.BookMapper"/>
    </mappers>
</configuration>

参考官网：mybatis映射器mappers
https://mybatis.org/mybatis-3/zh/configuration.html#mappers
在这里插入图片描述

Book:

package com.yzh7.entity;

import lombok.Data;

import java.util.Date;

@Data
public class Book {
//    book_id,book_name,author,price,publisher,pub_date

    private Integer bookId;
    private String bookName;
    private String author;
    private Double price;
    private String publisher;
    private Date pubDate;

}

BookMapper:

package com.yzh7.mapper;


import com.yzh7.entity.Book;
import org.apache.ibatis.annotations.Param;

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

public interface BookMapper {
    List<Map> listAll();
    List<Book> listAll2();
    Book getById(Integer bookId);

    int insert(Book book);
    int update(Book book);
    int delete(Integer bookId);

    Book getByNameAndAuthor(@Param("bn") String bookName,@Param("at") String author);

    Book getByMap(Map map);

    Book getByBook(Book book);

    List<Book> listByBookName(String bookName);




}

BookMapper.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="com.yzh7.mapper.BookMapper">

<!--     book_id,book_name,author,price,publisher,pub_date-->

    <select id="listAll" resultType="map">
        select * from tb_book
    </select>
    <select id="listAll2" resultType="book">
        select * from tb_book
    </select>
    <select id="getById" parameterType="int" resultType="book">
        select * from tb_book
        where book_id=#{bookId}
    </select>
    <insert id="insert" parameterType="book">
        insert into tb_book
        (book_name,author,price,publisher,pub_date)
        values
        (#{bookName},#{author},#{price},#{publisher},#{pubDate})   <!-- # -->
    </insert>
    <update id="update" parameterType="book">
        update tb_book
        set book_name=#{bookName},author=#{author},price=#{price},publisher=#{publisher},pub_date=#{pubDate}
        where book_id=#{bookId}
    </update>
    <delete id="delete" parameterType="int">
        delete from tb_book
        where book_id=#{bookId}
    </delete>

    <select id="getByNameAndAuthor" resultType="book">
        select * from tb_book
        where book_name=#{bn} and author=#{at}
    </select>

    <select id="getByMap" parameterType="map" resultType="book">
        select * from tb_book
        where book_name=#{bookName} and author=#{author}
    </select>

    <select id="getByBook" parameterType="book" resultType="book">
        select * from tb_book
        where book_name=#{bookName} and author=#{author}
    </select>

    <select id="listByBookName" resultType="book">
        select * from tb_book
        where book_name like '%${value}%'
    </select>

</mapper>

demo2 :

package com.yzh7.test;

import com.yzh7.entity.Book;
import com.yzh7.mapper.BookMapper;
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 org.junit.After;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class demo2 {

    @Test
    public void TestGetById(){
        BookMapper bookMapper=session.getMapper(BookMapper.class);
        Book book=bookMapper.getById(2);
        System.out.println("book1:"+book);
    }
    @Test
    public void testGetByNameAndAuthor(){
        BookMapper bookMapper=session.getMapper(BookMapper.class);
        Book book=bookMapper.getByNameAndAuthor("图书2","作者2");
        System.out.println("book2:"+book);
    }

    @Test
    public void testGetByMap(){
        BookMapper bookMapper=session.getMapper(BookMapper.class);
        Map map=new HashMap();
        map.put("bookName","图书2");
        map.put("author","作者2");
        Book book=bookMapper.getByMap(map);
        System.out.println("book3:"+book);
    }

    @Test
    public void testGetByBook(){
        BookMapper bookMapper=session.getMapper(BookMapper.class);
        Book b=new Book();
        b.setBookName("图书2");
        b.setAuthor("作者2");
        Book book=bookMapper.getByBook(b);
        System.out.println("book4:"+book);
    }

    @Test
    public void testListByBookName(){
        BookMapper bookMapper=session.getMapper(BookMapper.class);
        List<Book> book=bookMapper.listByBookName("图");
        System.out.println("book5:"+book);
    }



    private static SqlSessionFactory factory;    //静态
    private SqlSession session;

    @BeforeClass
    public static void befCla() throws IOException {
        String resource = "mybatis_config.xml";   //mybatis_config.xml
        InputStream inputStream = Resources.getResourceAsStream(resource);
        factory = new SqlSessionFactoryBuilder().build(inputStream);
    }

    @Before
    public void bf(){
        session=factory.openSession();
    }

    @After
    public void af(){
        session.commit();
        session.close();
    }
}



// A code block
var foo = 'bar';

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