package com.rainbowsea.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;
public class SqlSessionUtil {
    // 工具類的構(gòu)造方法一般都是私有話化的
    // 工具類中所有的方法都是靜態(tài)的，直接類名即可調(diào)用，不需要 new 對(duì)象
    // 為了防止new對(duì)象，構(gòu)造方法私有化。
    private SqlSessionUtil() {
    }
    private static SqlSessionFactory sessionFactory = null;
    // 靜態(tài)代碼塊，類加載時(shí)執(zhí)行
    // SqlSessionUtil 工具類在進(jìn)行第一次加載的時(shí)候，解析mybatis-config.xml 文件，創(chuàng)建SqlSessionFactory對(duì)象。
    static {
        // 獲取到  SqlSessionFactoryBuilder 對(duì)象
        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        // 獲取到SqlSessionFactory 對(duì)象
        // SQlsessionFactory對(duì)象，一個(gè)SqlSessionFactory對(duì)應(yīng)一個(gè) environment, 一個(gè)environment通常是一個(gè)數(shù)據(jù)庫(kù)
        try {
            sessionFactory = sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("mybatis-config.xml"));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
    /**
     * 獲取會(huì)話對(duì)象
     * @return SqlSession
     */
    public static SqlSession openSession() {
        // 獲取到 SqlSession 對(duì)象
        SqlSession sqlSession = sessionFactory.openSession();
        return sqlSession;
    }
}

<?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.rainbowsea</groupId>
    <artifactId>mybatis-002-crud</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
    <dependencies>
<!--              mybatis依賴 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.10</version>
        </dependency>
<!--    mysql驅(qū)動(dòng)器-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.30</version>
        </dependency>
<!--        引入 junit4 依賴-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
        <!--        引入 logback的依賴，這個(gè)日志框架實(shí)現(xiàn)了slf4j 規(guī)范-->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.11</version>
        </dependency>
    </dependencies>
</project>

<?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>
    <!--    開(kāi)啟mybatis 對(duì)標(biāo)準(zhǔn)日志的實(shí)現(xiàn)-->
    <!--    如果導(dǎo)入的第三方框架的日志，沒(méi)有下面這個(gè) settings 也是可以的-->
    <!--    <settings>-->
    <!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
    <!--    </settings>-->
    <environments default="development">
        <environment id="development">
            <!--            MANAGED 沒(méi)有用第三框架管理的話，都是會(huì)被提交的，沒(méi)有事務(wù)上的管理了。-->
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="MySQL123"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--sql映射文件創(chuàng)建好之后，需要將該文件路徑配置到這里-->
        <!--        執(zhí)行XxxMapper.xml 文件的路徑-->
        <!--        resource 屬性自動(dòng)會(huì)從類的根路徑下開(kāi)始查找資源-->
        <!--        <mapper resource="CarMapper.xml"/>-->
        <!--        <mapper resource="com/CarMapper2.xml"/>-->
        <!--        url屬性: 從絕對(duì)路徑當(dāng)中加載資源。-->
        <!--        語(yǔ)法格式：file:///絕對(duì)路徑-->
        <!--        <mapper url="file:///e:/CarMapper.xml"></mapper>-->
        <mapper resource="CarMapper.xml"></mapper>
    </mappers>
</configuration>

<?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">
<!--namespace先隨意寫(xiě)一個(gè)-->
<mapper namespace="rainbowsea">
</mapper>

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
    <!-- 控制臺(tái)輸出 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <!--格式化輸出：%d表示日期，%thread表示線程名，%-5level：級(jí)別從左顯示5個(gè)字符寬度%msg：日志消息，%n是換行符-->
            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
    </appender>
    <!--mybatis log configure-->
    <logger name="com.apache.ibatis" level="TRACE"/>
    <logger name="java.sql.Connection" level="DEBUG"/>
    <logger name="java.sql.Statement" level="DEBUG"/>
    <logger name="java.sql.PreparedStatement" level="DEBUG"/>
    <!-- 日志輸出級(jí)別,logback日志級(jí)別包括五個(gè)：TRACE < DEBUG < INFO < WARN < ERROR -->
    <root level="DEBUG">
        <appender-ref ref="STDOUT"/>
        <appender-ref ref="FILE"/>
    </root>
</configuration>

<?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">
<!--namespace先隨便寫(xiě)-->
<mapper namespace="car">
    <insert id="insertCar">
        insert into t_car(car_num,brand,guide_price,produce_time,car_type) values('103', '奔馳E300L', 50.3, '2022-01-01', '燃油車')
    </insert>
</mapper>

// JDBC中使用 ? 作為占位符。那么MyBatis中會(huì)使用什么作為占位符呢？
String sql = "insert into t_car(car_num,brand,guide_price,produce_time,car_type) values(?,?,?,?,?)";
// ......
// 給 ? 傳值。那么MyBatis中應(yīng)該怎么傳值呢？
ps.setString(1,"103");
ps.setString(2,"奔馳E300L");
ps.setDouble(3,50.3);
ps.setString(4,"2022-01-01");
ps.setString(5,"燃油車");

<?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">
<!--namespace先隨意寫(xiě)一個(gè)-->
<mapper namespace="rainbowsea">
<!--	insert語(yǔ)句，id是這個(gè)條SQL語(yǔ)句的唯一標(biāo)識(shí)，這個(gè)id就代表了這條SQL語(yǔ)句 -->
	<insert id="insertCar">
		insert into t_car(id,car_num,brand,guide_price,produce_time,car_type)
		values (null,#{k1},#{k2},#{k3},#{k4},#{k5})
<!--  map.get("fdsd") 找，結(jié)果找不到 = null-->
	</insert>
</mapper>

map.put("k1","111");
map.put("k2","比亞迪漢");
map.put("k3",10.0);
map.put("k4","2020-11-11");
map.put("k5","電車");

// 執(zhí)行sql語(yǔ)句
// insert方法的參數(shù):
// 第一個(gè)參數(shù):sqlId；從CarMapper.xml 文件中復(fù)制,的對(duì)于是insert SQL 語(yǔ)句的 id 信息
// 第二個(gè)參數(shù): 封裝數(shù)據(jù)的對(duì)象，這里為 Map 集合
int count = sqlSession.insert("insertCar", map);

insert into t_car(id,car_num,brand,guide_price,produce_time,car_type) values (null,#{fdsd},#{k2},#{k3},#{k4},#{k5})
注意：#{這里寫(xiě)什么？寫(xiě)map集合的key,如果key不存在，獲取的是null}

package com.rainbowsea.mybatis.pojo;
public class Car {
    //數(shù)據(jù)表當(dāng)中的字段應(yīng)該和pojo類的屬性一一對(duì)應(yīng)
    // 建議使用包裝類，這樣可以防止 null 的問(wèn)題：int = null; 不行，Int = null 可以
    private Long id;
    private String carNum;
    private String brand;
    private Double guiderPrice;
    private String produceTime;
    private String carType;
    public Car() {
    }
    public Car(Long id, String carNum, String brand, Double guiderPrice, String produceTime, String carType) {
        this.id = id;
        this.carNum = carNum;
        this.brand = brand;
        this.guiderPrice = guiderPrice;
        this.produceTime = produceTime;
        this.carType = carType;
    }
    @Override
    public String toString() {
        return "Car{" +
                "id=" + id +
                ", carNum='" + carNum + '\'' +
                ", brand='" + brand + '\'' +
                ", guiderPrice=" + guiderPrice +
                ", produceTime='" + produceTime + '\'' +
                ", carType='" + carType + '\'' +
                '}';
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getCarNum() {
        return carNum;
    }
/*    public String getXyz() {
        return carNum;
    }*/
    public void setCarNum(String carNum) {
        this.carNum = carNum;
    }
    public String getBrand() {
        return brand;
    }
    public void setBrand(String brand) {
        this.brand = brand;
    }
    public Double getGuiderPrice() {
        return guiderPrice;
    }
    public void setGuiderPrice(Double guiderPrice) {
        this.guiderPrice = guiderPrice;
    }
    public String getProduceTime() {
        return produceTime;
    }
    public void setProduceTime(String produceTime) {
        this.produceTime = produceTime;
    }
    public String getCarType() {
        return carType;
    }
    public void setCarType(String carType) {
        this.carType = carType;
    }
}

 public void testInsertCarByPOJO() {
        SqlSession sqlSession = SqlSessionUtil.openSession();
        // 封裝數(shù)據(jù)
        Car car = new Car(null, "333", "比亞迪泰", 30.0, "2020-11-11", "新能源");
        // 執(zhí)行SQL
        int count = sqlSession.insert("insertCar", car); // ORM       // 對(duì)應(yīng)XxxMapper.xml 上的id
        System.out.println(count);
        sqlSession.commit();
        sqlSession.close();
    }

@Test
    public void testDeleteById() {
        SqlSession sqlSession = SqlSessionUtil.openSession();
        // 執(zhí)行SQL語(yǔ)句
        sqlSession.delete("deleteById",44); // 如果只要一個(gè)值的時(shí)候，就不需要對(duì)應(yīng)上的的 Object 類型了
        sqlSession.commit(); // 提交
        sqlSession.close(); // 關(guān)閉
    }

<update id="updateById">
		update t_car set car_num = #{carNum}, brand=#{brand}, guide_price=#{guiderPrice},produce_time=#{produceTime},
		                 car_type=#{carType} where id =#{id}
	</update>

   public void testUpdateById() {
        SqlSession sqlSession = SqlSessionUtil.openSession();
        Car car = new Car(46L, "999", "凱美瑞", 30.3, "1999-11-10", "燃油車");
        // 執(zhí)行SQL語(yǔ)句
        int count = sqlSession.update("updateById", car);
        System.out.println(count);
        sqlSession.commit();
        sqlSession.close();
    }

<select id="selectById" resultType="com.rainbowsea.mybatis.pojo.Car">
		select id,car_num as carNum, brand, guide_price as guiderPrice,
		produce_time as produceTime,
		car_type as carType
		from t_car
		where id= #{id}
	</select>

<select id="selectById" resultType="com.rainbowsea.mybatis.pojo.Car">
		select id,car_num as carNum, brand, guide_price as guiderPrice,
		produce_time as produceTime,
		car_type as carType
		from t_car
		where id= #{id}
	</select>

<select id="selectAll" resultType="com.rainbowsea.mybatis.pojo.Car">
		select
		       id,car_num as carNum, brand, guide_price as guiderPrice,
			   produce_time as produceTime,
			   car_type as carType
		from
		       t_car
	</select>

   <select id="selectAll" resultType="com.rainbowsea.mybatis.pojo.Car">
      select
             id,car_num as carNum, brand, guide_price as guiderPrice,
            produce_time as produceTime,
            car_type as carType
      from
             t_car
   </select>
  List<Car> cars = sqlSession.selectList("selectAll");
注意: resultType 還是指定封裝的結(jié)果集的類型，不是指定List類型，是指定List集合中元素的類型
selectList 方法，mybatis通過(guò)這個(gè)方法就可以得知你需要一個(gè)List集合，它會(huì)自動(dòng)給你返回一個(gè)List集合

<?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">
<!--namespace先隨意寫(xiě)一個(gè)-->
<mapper namespace="rainbowsea">
	<select id="selectAll" resultType="com.rainbowsea.mybatis.pojo.Car">
		select
			id,car_num as carNum, brand, guide_price as guiderPrice,
			produce_time as produceTime,
			car_type as carType
		from
			t_car
	</select>
</mapper>

<?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>
    <!--    開(kāi)啟mybatis 對(duì)標(biāo)準(zhǔn)日志的實(shí)現(xiàn)-->
    <!--    如果導(dǎo)入的第三方框架的日志，沒(méi)有下面這個(gè) settings 也是可以的-->
    <!--    <settings>-->
    <!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
    <!--    </settings>-->
    <environments default="development">
        <environment id="development">
            <!--            MANAGED 沒(méi)有用第三框架管理的話，都是會(huì)被提交的，沒(méi)有事務(wù)上的管理了。-->
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="MySQL123"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!--sql映射文件創(chuàng)建好之后，需要將該文件路徑配置到這里-->
        <!--        執(zhí)行XxxMapper.xml 文件的路徑-->
        <!--        resource 屬性自動(dòng)會(huì)從類的根路徑下開(kāi)始查找資源-->
        <!--        <mapper resource="CarMapper.xml"/>-->
        <!--        <mapper resource="com/CarMapper2.xml"/>-->
        <!--        url屬性: 從絕對(duì)路徑當(dāng)中加載資源。-->
        <!--        語(yǔ)法格式：file:///絕對(duì)路徑-->
        <!--        <mapper url="file:///e:/CarMapper.xml"></mapper>-->
        <mapper resource="CarMapper.xml"></mapper>
        <mapper resource="UserMapper.xml"></mapper>
    </mappers>
</configuration>

 public void testNamespace() {
        SqlSession sqlSession = SqlSessionUtil.openSession();
        // 執(zhí)行SQL語(yǔ)句
        // 正確的完整寫(xiě)法:namespace.id
        List<Car> cars = sqlSession.selectList("selectAll");
        // 遍歷
        cars.forEach(car -> {
            System.out.println(car);
        });
        //sqlSession.commit();  查詢不用提交,沒(méi)有事務(wù)問(wèn)題
        sqlSession.close();
    }

@Test
    public void testNamespace() {
        SqlSession sqlSession = SqlSessionUtil.openSession();
        // 執(zhí)行SQL語(yǔ)句
        // 正確的完整寫(xiě)法:namespace.id
        List<Car> cars = sqlSession.selectList("rainbowsea2.selectAll");
        // 遍歷
        cars.forEach(car -> {
            System.out.println(car);
        });
        //sqlSession.commit();  查詢不用提交,沒(méi)有事務(wù)問(wèn)題
        sqlSession.close();
    }