🍁查询
🔥解决属性名和字段名不一致的问题
数据库表的字段名和实体类的属性名不一致，则不能自动封装数据。
1.起别名
缺点：每次查询都要定义一次别名- 2.sql片段
缺点：不灵活 3.resultMap
1.定义resultMap标签 2.在select标签中，使用resultMap属性替换resultType替换。
- 2.sql片段
<!-- 1.起别名-->
<!-- <select id="selectAll" resultType="brand">
select id,brand_name as brandName,company_name as companyName,ordered,description,status
from tb_brand;
</select>-->
<!--2.sql片段-->
<!--<sql id="sql">
id,brand_name as brandName,company_name as companyName,ordered,description,status
</sql>
<select id="selectAll" resultType="brand">
select <include refid="sql"/>
from tb_brand;
</select>-->
<!-- 3.resultMap-->
<resultMap id="brandResultMap" type="brand">
<result column="brand_name" property="brandName"></result>
<result column="company_name" property="companyName"></result>
</resultMap>
<select id="selectAll" resultMap="brandResultMap">
select * from tb_brand;
</select>🔥模糊查询
- java代码执行的时候，传递通配符% %
//接收参数
int status=1;
String companyName="华为";
String brandName="华为";
//处理参数
companyName="%"+companyName+"%";
brandName="%"+brandName+"%";- 在sql拼接中使用通配符！
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
where status =#{status}
and company_name like "%"#{companyName}"%"
and brand_name like "%"#{brandName}"%"
;
</select>🔥特殊字符处理
在通过id查询数据时，查询条件是id小于某个数时。
- 转义字符
- CDATA区
select * from tb_brand
where id
<![CDATA[
<
]]>
#{id};🔥参数占位符
- ${}：拼sql,存在sql注入问题
{}：会将其替换为？，防止sql注入
🔥参数接收
- 1，散装参数：如果方法中有多个参数，需要使用@param("sql参数占位符名称")
List<Brand> selectByCondition(@Param("status") int status,@Param("companyName") String companyName,@Param("brandName") String brandName);- 2.实体类封装参数
List<Brand> selectByCondition(Brand brand);- 3.Map集合
List<Brand> selectByCondition(Map map);🔥动态条件查询
状态，公司名称，品牌名称，任意一个就可以查询数据
- 1.恒等式
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
where 1=1
<if test="status !=null">
and status =#{status}
</if>
<if test="companyName !=null and companyName !=''">
and company_name like #{companyName}
</if>
<if test="brandName !=null and brandName !=''">
and brand_name like #{brandName}
</if>
</select>- 2. 替换where关键字
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
<where>
<if test="status !=null">
and status =#{status}
</if>
<if test="companyName !=null and companyName !=''">
and company_name like #{companyName}
</if>
<if test="brandName !=null and brandName !=''">
and brand_name like #{brandName}
</if>
</where>
</select>🔥单条件动态条件查询
<!--<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
where
<choose>
<when test="status !=null">
status =#{status}
</when>
<when test="companyName !=null and companyName !=''">
company_name like #{companyName}
</when>
<when test="brandName !=null and brandName !=''">
brand_name like #{brandName}
</when>
<!–一个都没有选择–>
<otherwise>
1=1
</otherwise>
</choose>
</select>-->
<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
<where>
<choose>
<when test="status !=null">
status =#{status}
</when>
<when test="companyName !=null and companyName !=''">
company_name like #{companyName}
</when>
<when test="brandName !=null and brandName !=''">
brand_name like #{brandName}
</when>
</choose>
</where>
</select>🍁添加
🔥添加全部数据
<insert id="add" >
insert into tb_brand(brand_name,company_name,ordered,description,status)
values (#{brandName},#{companyName},#{ordered},#{description},#{status});
</insert>🔥返回添加数据的主键
<insert id="add" useGeneratedKeys="true" keyProperty="id">
insert into tb_brand(brand_name,company_name,ordered,description,status)
values (#{brandName},#{companyName},#{ordered},#{description},#{status});
</insert>🍁修改
🔥修改全部数据
根据id修改全部数据：
<update id="update">
update tb_brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description},status=#{status}
where id=#{id};
</update>🔥修改动态字段
根据id修改可以修改任意个字段：
<update id="update">
update tb_brand
<set>
<if test="brandName !=null and brandName !=''">
brand_name=#{brandName},
</if>
<if test="companyName !=null and companyName !=''">
company_name=#{companyName},
</if>
<if test="ordered !=null">
ordered=#{ordered},
</if>
<if test="description !=null and description !=''">
description=#{description},
</if>
<if test="status !=null">
status=#{status}
</if>
</set>
where id=#{id};
</update>🍁删除
🔥通过id删除数据
<delete id="deleteById">
delete from tb_brand where id=#{id};
</delete>🔥通过id进行批量删除
mybatis会将数组参数，封装成一个Map集合
1.默认：array=数组
2.使用@param注解改变map集合的默认key的名称
<delete id="deleteByIds">
delete from tb_brand where id
in
<foreach collection="ids" item="id" separator="," open="(" close=")">
<!--<foreach collection="array" item="id" separator="," open="(" close=")">-->
#{id}
</foreach>
;
</delete>🍁MyBatis事务
注意**增删改需要提交事务！**- openSession():默认开启事务，进行增删改操作后，需要使用sqlSession.commit(); 手动提交事务。
//4.提交事务
sqlSession.commit();2.openSession(true);可以设置为自动提交事务和关闭事务。
SqlSession sqlSession = sqlSessionFactory.openSession(true);🍁增删改查案例分析
🔥数据库
创建数据库：mybatis
设计表：
往表里添加数据。
🔥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>com.jkj</groupId>
<artifactId>maven-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<!--import dependencies-->
<dependencies>
<!--mysql driver-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<!--mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.6</version>
</dependency>
<!--junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
</project>🔥brand实体类：
package com.jkj.pojo;
public class Brand {
private Integer id;
private String brandName;
private String companyName;
private Integer ordered;
private String description;
private Integer status;
public Brand() {
}
public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {
this.id = id;
this.brandName = brandName;
this.companyName = companyName;
this.ordered = ordered;
this.description = description;
this.status = status;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getBrandName() {
return brandName;
}
public void setBrandName(String brandName) {
this.brandName = brandName;
}
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
public Integer getOrdered() {
return ordered;
}
public void setOrdered(Integer ordered) {
this.ordered = ordered;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Integer getStatus() {
return status;
}
public void setStatus(Integer status) {
this.status = status;
}
@Override
public String toString() {
return "Brand{" +
"id=" + id +
", brandName='" + brandName + '\'' +
", companyName='" + companyName + '\'' +
", ordered=" + ordered +
", description='" + description + '\'' +
", status=" + status +
'}';
}
}
🔥BrandMapper:
package com.jkj.Mapper;
import com.jkj.pojo.Brand;
import com.jkj.pojo.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
import java.util.Map;
public interface BrandMapper {
//查询所有
List<Brand> selectAll();
//查询详情，通过id查询
Brand selectById(int id);
/*条件查询
参数接收
1，散装参数：如果方法中有多个参数，需要使用@param("sql参数占位符名称")
2.实体类封装参数
3.Map集合
*/
//List<Brand> selectByCondition(@Param("status") int status,@Param("companyName") String companyName,@Param("brandName") String brandName);
//List<Brand> selectByCondition(Brand brand);
List<Brand> selectByCondition(Map map);
//单条件动态条件查询
List<Brand> selectByConditionSingle(Brand brand);
//添加
void add(Brand brand);
//修改全部字段
int update(Brand brand);
//通过id删除数据
void deleteById(int id);
//批量删除
void deleteByIds(@Param("ids") int[] ids);
}
🔥mybatis-config.xml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 core file-->
<configuration>
<!--起别名，不区分大小写-->
<typeAliases>
<package name="com.jkj.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<!--加载sql映射文件-->
<mappers>
<!--<mapper resource="com/jkj/Mapper/UserMapper.xml"/>-->
<!--Mapper代理方式-->
<package name="com.jkj.Mapper"/>
</mappers>
</configuration>
🔥BrandMapper.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.jkj.Mapper.BrandMapper">
<!--
数据库表的字段名和实体类的属性名不一致，则不能自动封装数据
1.起别名
缺点：每次查询都要定义一次别名
2.sql片段
缺点：不灵活
3.resultMap
1.定义resultMap标签
2.在select标签中，使用resultMap属性替换resultType替换
-->
<!--<select id="selectAll" resultType="com.jkj.pojo.Brand">
sel快捷键
select * from tb_brand;
</select>-->
<!-- 1.起别名-->
<!-- <select id="selectAll" resultType="brand">
select id,brand_name as brandName,company_name as companyName,ordered,description,status
from tb_brand;
</select>-->
<!--2.sql片段-->
<!--<sql id="sql">
id,brand_name as brandName,company_name as companyName,ordered,description,status
</sql>
<select id="selectAll" resultType="brand">
select <include refid="sql"/>
from tb_brand;
</select>-->
<!-- 3.resultMap-->
<resultMap id="brandResultMap" type="brand">
<result column="brand_name" property="brandName"></result>
<result column="company_name" property="companyName"></result>
</resultMap>
<select id="selectAll" resultMap="brandResultMap">
select * from tb_brand;
</select>
<!--通过id查询-->
<!--
参数占位符
${}：拼sql,存在sql注入问题
#{}：会将其替换为？，防止sql注入
-->
<!--<select id="selectById" resultMap="brandResultMap">
select * from tb_brand where id=#{id};
</select>-->
<!--特殊字符处理
1.转义字符
2.CDATA区
-->
<select id="selectById" resultMap="brandResultMap">
select * from tb_brand
where id
<![CDATA[
<
]]>
#{id};
</select>
<!--条件查询-->
<!--<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
where status =#{status}
and company_name like #{companyName}
and brand_name like #{brandName}
;
</select>-->
<!--动态条件查询-->
<!--状态，公司名称，品牌名称，任意一个就可以查询数据
-->
<!-- 1.恒等式-->
<!-- <select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
where 1=1
<if test="status !=null">
and status =#{status}
</if>
<if test="companyName !=null and companyName !=''">
and company_name like #{companyName}
</if>
<if test="brandName !=null and brandName !=''">
and brand_name like #{brandName}
</if>
</select>-->
<!-- 2.<where> 替换where关键字-->
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand
<where>
<if test="status !=null">
and status =#{status}
</if>
<if test="companyName !=null and companyName !=''">
and company_name like #{companyName}
</if>
<if test="brandName !=null and brandName !=''">
and brand_name like #{brandName}
</if>
</where>
</select>
<!--单条件动态查询-->
<!--<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
where
<choose>
<when test="status !=null">
status =#{status}
</when>
<when test="companyName !=null and companyName !=''">
company_name like #{companyName}
</when>
<when test="brandName !=null and brandName !=''">
brand_name like #{brandName}
</when>
<!–一个都没有选择–>
<otherwise>
1=1
</otherwise>
</choose>
</select>-->
<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
<where>
<choose>
<when test="status !=null">
status =#{status}
</when>
<when test="companyName !=null and companyName !=''">
company_name like #{companyName}
</when>
<when test="brandName !=null and brandName !=''">
brand_name like #{brandName}
</when>
</choose>
</where>
</select>
<!--添加数据-->
<!--<insert id="add" >
insert into tb_brand(brand_name,company_name,ordered,description,status)
values (#{brandName},#{companyName},#{ordered},#{description},#{status});
</insert>-->
<!--返回添加数据的主键-->
<insert id="add" useGeneratedKeys="true" keyProperty="id">
insert into tb_brand(brand_name,company_name,ordered,description,status)
values (#{brandName},#{companyName},#{ordered},#{description},#{status});
</insert>
<!--修改全部字段-->
<!--<update id="update">
update tb_brand set brand_name=#{brandName},company_name=#{companyName},ordered=#{ordered},description=#{description},status=#{status}
where id=#{id};
</update>-->
<!--修改动态字段，可以任意个字段-->
<update id="update">
update tb_brand
<set>
<if test="brandName !=null and brandName !=''">
brand_name=#{brandName},
</if>
<if test="companyName !=null and companyName !=''">
company_name=#{companyName},
</if>
<if test="ordered !=null">
ordered=#{ordered},
</if>
<if test="description !=null and description !=''">
description=#{description},
</if>
<if test="status !=null">
status=#{status}
</if>
</set>
where id=#{id};
</update>
<!--通过id删除数据-->
<delete id="deleteById">
delete from tb_brand where id=#{id};
</delete>
<!--批量删除-->
<!--
mybatis会将数组参数，封装成一个Map集合
1.默认：array=数组
2.使用@param注解改变map集合的默认key的名称
-->
<delete id="deleteByIds">
delete from tb_brand where id
in
<foreach collection="ids" item="id" separator="," open="(" close=")">
<!--<foreach collection="array" item="id" separator="," open="(" close=")">-->
#{id}
</foreach>
;
</delete>
</mapper>🔥测试类：
package com.jkj.test;
import com.jkj.Mapper.BrandMapper;
import com.jkj.Mapper.UserMapper;
import com.jkj.pojo.Brand;
import com.jkj.pojo.User;
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.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MyBatisTest {
@Test
public void selectAll() throws IOException {
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
List<Brand> brands = mapper.selectAll();
System.out.println(brands);
//4.释放资源
sqlSession.close();
/* [Brand{id=1, brandName='华为', companyName='华为有限技术公司', ordered=100, description='华为牛逼', status=1},
Brand{id=2, brandName='小米', companyName='小米有限技术公司', ordered=50, description='小米不孬', status=1},
Brand{id=3, brandName='荣耀', companyName='荣耀有限技术公司', ordered=20, description='荣耀很中', status=1}]*/
}
@Test
public void selectById() throws IOException {
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
Brand brand = mapper.selectById(2);
System.out.println(brand);
//4.释放资源
sqlSession.close();
/*Brand{id=1, brandName='华为', companyName='华为有限技术公司', ordered=100, description='华为牛逼', status=1}*/
}
@Test
public void selectByCondition() throws IOException {
//接收参数
int status=1;
String companyName="华为";
String brandName="华为";
//处理参数
companyName="%"+companyName+"%";
brandName="%"+brandName+"%";
/*//封装对象
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);*/
//创建Map集合
Map map=new HashMap();
/*map.put("status",status);*/
/*map.put("companyName",companyName);*/
map.put("brandName",brandName);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
//List<Brand> brands = mapper.selectByCondition(status, companyName, brandName);
//List<Brand> brands = mapper.selectByCondition(brand);
List<Brand> brands = mapper.selectByCondition(map);
System.out.println(brands);
//4.释放资源
sqlSession.close();
/*[Brand{id=1, brandName='华为', companyName='华为有限技术公司', ordered=100, description='华为牛逼', status=1}]*/
}
@Test
public void selectByConditionSingle() throws IOException {
//接收参数
int status=1;
String companyName="华为";
String brandName="华为";
//处理参数
companyName="%"+companyName+"%";
brandName="%"+brandName+"%";
//封装对象
Brand brand = new Brand();
/* brand.setStatus(status);
brand.setCompanyName(companyName);*/
brand.setBrandName(brandName);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
List<Brand> brands = mapper.selectByConditionSingle(brand);
System.out.println(brands);
//4.释放资源
sqlSession.close();
}
@Test
public void add() throws IOException {
//接收参数
int status=0;
String companyName="今麦郎";
String brandName="今麦郎";
int ordered=200;
String description="今麦郎可以";
//封装对象
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
brand.setOrdered(ordered);
brand.setDescription(description);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
mapper.add(brand);
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void add2() throws IOException {
//接收参数
int status=1;
String companyName="农夫山泉";
String brandName="农夫山泉";
int ordered=200;
String description="农夫山泉真甜";
//封装对象
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
brand.setOrdered(ordered);
brand.setDescription(description);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
mapper.add(brand);
//获取添加数据的主键
Integer id = brand.getId();
System.out.println(id); //6
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void TestUpdate() throws IOException {
//接收参数
int status=1;
String companyName="农夫山泉plus";
String brandName="农夫山泉plus";
int ordered=200;
String description="农夫山泉甜甜甜";
int id=5;
//封装对象
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
brand.setOrdered(ordered);
brand.setDescription(description);
brand.setId(id);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
int count = mapper.update(brand);
System.out.println(count); //受影响的行数
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void TestUpdate1() throws IOException {
//接收参数
int status=1;
String companyName="农夫山泉plus";
String brandName="农夫山泉plus";
int ordered=200;
String description="我只是大自然的搬运工";
int id=5;
//封装对象
Brand brand = new Brand();
/* brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
brand.setOrdered(ordered);*/
brand.setDescription(description);
brand.setId(id);
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
int count = mapper.update(brand);
System.out.println(count); //受影响的行数
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void TestDeleteById() throws IOException {
int id=5;
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
mapper.deleteById(id);
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void TestDeleteByIds() throws IOException {
int [] ids={4,5,6};
//1.加载MyBatis的核心配置文件获取sqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
//3.执行sql
mapper.deleteByIds(ids);
//4.提交事务
sqlSession.commit();
//5.释放资源
sqlSession.close();
}
@Test
public void TestSelectAll() throws IOException {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取sqlSession,执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper mapper = (UserMapper) sqlSession.getMapper(UserMapper.class);
//3.执行sql
List<User> users = mapper.selectAll();
System.out.println(users);
//4.释放资源
sqlSession.close();
//[User{id=1, username='小马哥', password='111', gender='男', addr='北京'},
// User{id=2, username='小飞侠', password='222', gender='男', addr='上海'},
// User{id=3, username='马奎斯', password='333', gender='女', addr='西班牙'}]
}
}
