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SpringBootMVC04 Spirngboot第四天Mybatis/readme.md

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+# mybatis
+
+MyBatis是一个优秀的持久层框架，它对jdbc的操作数据库的过程进行封装，使开发者只需要关注SQL本身，而不需要花费精力去处理例如注册驱动、创建connection、创建statement、手动设置参数、结果集检索等jdbc繁杂的过程代码。
+
+
+
+## 配置文件
+
+
+
+### MybatisConfig.xml
+
+  SSM中需要配置
+
+- 数据url
+- 数据库连接池
+- 映射文件
+- 事务
+
+在SpringBoot中整合到property中了
+
+### Mapper.xml
+
+#### namespace
+
+接口绑定 和接口
+
+就可以不用写DAO实现类，Mybatis会通过绑定自动找到要执行的sql语句。
+
+**resultMap**
+
+结果集对应到实体类的字段到属性映射
+
+## xml 方式
+
+## 传统方式
+
+#### xml配置
+
+
+
+```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">  
+
+<!-- version: $Id$ -->  
+<configuration>  
+    <!-- 引用JDBC属性的配置文件 -->  
+    <properties resource="database.properties" />  
+
+    <environments default="development">  
+        <environment id="development">  
+            <!-- 使用JDBC的事务管理 -->  
+            <transactionManager type="JDBC" />  
+            <!-- POOLED ：JDBC连接对象的数据源连接池的实现，不直接支持第三方数据库连接池 -->  
+            <dataSource type="POOLED">  
+                <property name="driver" value="${database.driver}" />  
+                <property name="url" value="${database.url}" />  
+                <property name="username" value="${database.username}" />  
+                <property name="password" value="${database.password}" />  
+            </dataSource>  
+        </environment>  
+
+    </environments>  
+
+    <!-- ORM映射文件 -->  
+    <mappers>  
+        <!-- 注解的方式 -->  
+        <mapper class="com.iflytek.dao.mapper.AccountMapper" />  
+        <!-- XML的方式 -->  
+        <mapper resource="com/mashibing/dao/xml/AccountMapper.xml" />  
+        <!-- 这里对于注解，还可以通过<package name="com.mashibing.dao.mapper"/> -->  
+    </mappers>  
+</configuration>  
+```
+
+
+
+#### Service 配置
+
+
+
+```java
+public class AccountService {  
+
+    public boolean insertAccount(Account account) {  
+        boolean flag = false;  
+        SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();  
+        try {  
+            accountMapper accountMapper = sqlSession.getMapper(AccountMapper.class);  
+            int result = accountMapper.insert(student);  
+            if (result > 0) {  
+                flag = true;  
+            }  
+            sqlSession.commit();  
+        } finally {  
+            sqlSession.close();  
+        }  
+        return flag;  
+    }  
+
+
+    public Student getAccountById(int id) {  
+        SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();  
+        try {  
+            AccountMapper AccountMapper = sqlSession.getMapper(AccountMapper.class);  
+            return AccountMapper.selectByPrimaryKey(id);  
+        } finally {  
+            sqlSession.close();  
+        }  
+    }  
+
+
+    public List<Student> getAllStudents() {  
+        SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();  
+        try {  
+            StudentMapper StudentMapper = sqlSession.getMapper(StudentMapper.class);  
+            return StudentMapper.selectByExample(new StudentExample());  
+        } finally {  
+            sqlSession.close();  
+        }  
+    }  
+
+
+    public boolean updateAccount(Account account) {  
+        SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();  
+        boolean flag = false;  
+        try {  
+            AccountMapper AccountMapper = sqlSession.getMapper(AccountMapper.class);  
+            int result = AccountMapper.updateByPrimaryKey(Account);  
+            if (result > 0) {  
+                flag = true;  
+            }  
+            sqlSession.commit();  
+        } finally {  
+            sqlSession.close();  
+        }  
+        return flag;  
+
+    }  
+
+
+    public boolean deleteAccount(int id) {  
+        SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();  
+        boolean flag = false;  
+        try {  
+            AccountMapper AccountMapper = sqlSession.getMapper(AccountMapper.class);  
+            int result = AccountMapper.deleteByPrimaryKey(id);  
+            if (result > 0) {  
+                flag = true;  
+            }  
+            sqlSession.commit();  
+        } finally {  
+            sqlSession.close();  
+        }  
+        return flag;  
+    }  
+
+}  
+```
+
+
+
+
+
+
+
+## 与SpringBoot整合
+
+### 引入依赖
+
+```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>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.1.6.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.example</groupId>
+	<artifactId>springboot03-mybatis</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>springboot03-mybatis</name>
+	<description>Demo project for Spring Boot</description>
+
+	<properties>
+		<java.version>1.8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-thymeleaf</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.mybatis.spring.boot</groupId>
+			<artifactId>mybatis-spring-boot-starter</artifactId>
+			<version>2.0.1</version>
+		</dependency>
+
+		<dependency>
+			<groupId>mysql</groupId>
+			<artifactId>mysql-connector-java</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-devtools</artifactId>
+		</dependency>
+
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>
+
+```
+
+
+
+### mapper
+
+``` 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.mashibing.springboot.mapper.AccountMapper">
+
+   <resultMap type="com.mashibing.springboot.mapper.Account" id="BaseResultMap">
+
+   	<result column="login_name" property="loginName"/>
+   	<result column="password" property="password"/>
+
+   </resultMap>
+
+
+    <insert id="save" parameterType="Account">
+        INSERT INTO account(login_name,password)
+        VALUES
+        (
+        #{loginName},#{password}
+        )
+    </insert>
+
+    <select id="findAll" resultMap="BaseResultMap">
+        select * from account
+    </select>
+
+</mapper>
+
+
+
+```
+
+### application.properties
+
+``` pr
+spring.datasource.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf8&useSSL=false&serverTimezone=UTC
+##数据库用户名
+spring.datasource.username=root
+##数据库密码
+spring.datasource.password=840416
+
+# 用来实例化mapper接口
+mybatis.type-aliases-package=com.mashibing.springboot.mapper
+# 对应的sql映射
+mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
+```
+
+### AccountMapper
+
+``` java
+package com.mashibing.springboot.mapper;
+
+import org.apache.ibatis.annotations.Mapper;
+
+@Mapper
+public interface AccountMapper {
+
+	void save(Account account);
+}
+
+
+```
+
+### Account
+
+``` java
+
+public class Account {
+	private int id;
+	private String loginName;
+	private String password;
+	private String nickName;
+	private int age;
+	private String location;
+	private int banlance;
+	public int getId() {
+
+```
+
+
+
+### 显示日志
+
+logging.level.com.mashibing.springboot.mapper=debug
+
+
+
+## 注解查询
+
+```java
+	@Select("select * from account1")
+	List<Account> findAll();
+
+```
+
+
+
+
+
+## 查找mapper接口
+
+### 在入口加入 MapperScan
+
+@MapperScan("com.mashibing.springboot.mapper")
+public class Springboot03MybatisApplication {
+
+### 每一个mapper接口上加入
+
+@Mapper
+public interface AccountMapper {
+
+## Mapper 自动生成
+
+### eclipse插件 市场搜素
+
+MyBatis Generator
+
+### 图形化
+
+https://github.com/zouzg/mybatis-generator-gui
+
+## 分页查询
+
+
+
+### 依赖
+
+```xml
+<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper-spring-boot-starter -->
+<dependency>
+    <groupId>com.github.pagehelper</groupId>
+    <artifactId>pagehelper-spring-boot-starter</artifactId>
+    <version>1.2.12</version>
+</dependency>
+
+```
+
+### Service
+
+```java
+	public Object findPage(int pageNum, int pageSize) {
+
+		PageHelper.startPage(pageNum, pageSize);
+		AccountExample example = new AccountExample();
+		return mapper.selectByExample(example );
+	}
+```
+