Spring Boot Mysql 数据库操作示例

本文默认你的开发环境.数据库已经安装好

想用使用数据库.我们需要现在pom文件中添加相应的依赖

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.imgod</groupId>
 <artifactId>testjpa</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>war</packaging>

<name>TestJpa</name>
 <description>Demo project for Spring Boot</description>

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.4.2.RELEASE</version>
   <relativePath /> <!-- lookup parent from repository -->
 </parent>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
 </properties>

<dependencies>
   <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-data-jpa</artifactId>
   </dependency>
   <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-web</artifactId>
   </dependency>

<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-tomcat</artifactId>
     <scope>provided</scope>
   </dependency>
   <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-test</artifactId>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>mysql</groupId>
     <artifactId>mysql-connector-java</artifactId>
   </dependency>
   <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-jdbc</artifactId>
   </dependency>
   <!-- 添加Hibernate依赖 -->
   <dependency>
     <groupId>org.hibernate</groupId>
     <artifactId>hibernate-core</artifactId>
   </dependency>
 </dependencies>

<build>
   <plugins>
     <plugin>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-maven-plugin</artifactId>
     </plugin>
   </plugins>
 </build>

</project>

我们的配置文件进行数据库的配置

application.properties:

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=imgod1
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.max-idle=10
spring.datasource.max-wait=10000
spring.datasource.min-idle=5
spring.datasource.initial-size=5
spring.jpa.properties.hibernate.hbm2ddl.auto=update

前面配置的是数据库信息,最后一行配置的是.如果我们定义的实体在数据库中没有对应的表的话.会帮我们自动创建

我们的实体类型

User.Java

package com.imgod.bean;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;

@Entity
@Table(name = "users")
public class User {
 @Id
 @GeneratedValue(strategy = GenerationType.AUTO)
 private int id;
 @NotNull
 private String email;
 @NotNull
 private String name;

public int getId() {
   return id;
 }

public void setId(int id) {
   this.id = id;
 }

public String getEmail() {
   return email;
 }

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

public String getName() {
   return name;
 }

public void setName(String name) {
   this.name = name;
 }

}

对应数据库中的user表,没有的话会自动创建

想对数据库进行操作,我们需要创建一个接口继承CrudRepository

UserDao.java

package com.imgod.dao;

import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import com.imgod.bean.User;
import java.lang.String;
import java.util.List;

@Transactional
@Repository
public interface UserDao extends CrudRepository<User, Integer> {
 //jpa 方法名就是查询语句,只要规法写方法名一切就都可以完成(当然.有时候会造成方法名又臭又长)
 User findByEmail(String email);//根据邮箱查询
 List<User> findByName(String name);//根据用户名查询

//select * from test.users where email='imgod@qq.com' and name='imgod';
 List<User> findByNameAndEmail(String name,String email);//根据用户名和邮箱进行查询

//select * from test.users where email='imgod@qq.com' and name='imgod4444' order by id desc;
 List<User> findByNameAndEmailOrderByIdDesc(String name,String email);//根据用户名和邮箱进行查询,排序

//select * from test.users where email='imgod@qq.com' and name='imgod4444' order by id desc limit 2;
 List<User> findTop2ByNameAndEmailOrderByIdDesc(String name,String email);//根据用户名和邮箱进行查询,排序,前两个

//根据邮箱进行分页查询
 List<User> findByEmail(String email,Pageable pageable);//根据用户名和邮箱进行查询
}

实现CrudRepository我们就可以对数据库进行一些基础操作了

如果我们想要实现更多的操作.需要自己按照严格的命名规则为方法定义方法名

下面就是我们重要的控制器的实现了:

package com.imgod.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageRequest;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.imgod.bean.User;
import com.imgod.dao.UserDao;

@RestController
public class UserController {
 @Autowired
 private UserDao userDao;

/**
  * 根据邮件去查找
  *
  * @param email
  * @return
  */
 @RequestMapping(value = "/findUserByEmail")
 public Object getUserByEmail(String email) {
   System.out.println("email:" + email);
   User user = userDao.findByEmail(email);
   if (null == user) {
     return "暂无数据";
   } else {
     return user;
   }

}

/**
  * 获取所有的用户信息
  *
  * @return
  */
 @RequestMapping(value = "/getall")
 public Object getAllUser() {
   List<User> list = (List<User>) userDao.findAll();
   if (null == list || list.size() == 0) {
     return "暂无数据";
   } else {
     return list;
   }

}

/**
  * 删除指定id用户
  *
  * @param id
  * @return
  */
 @RequestMapping(value = "/deleteUser")
 public Object deleteuUser(int id) {
   User user = userDao.findOne(id);
   if (null == user) {
     return "删除用户失败:" + id + "没找到该用户";
   } else {
     userDao.delete(id);
     return "删除用户成功:" + id;
   }

}

/**
  * 添加用户
  *
  * @param id
  * @param email
  * @param name
  * @return
  */
 @RequestMapping(value = "/adduser")
 public Object addUser(String id, String email, String name) {
   System.out.println("email:" + email);

int tempId = Integer.parseInt(id);
   System.out.println("tempId:" + tempId + "email:" + email + "name:" + name);

User tempUser = userDao.findOne(tempId);
   if (null == tempUser) {
     tempUser = new User();
     tempUser.setId(tempId);
   }
   tempUser.setEmail(email);
   tempUser.setName(name);
   User resultUser = userDao.save(tempUser);
   if (null == resultUser) {
     return "新增用户失败";
   } else {
     return "新增用户:" + resultUser.getName();
   }

}

// 条件查询

/**
  * 获取姓名和邮箱是指定内容的用户
  *
  * @return
  */
 @RequestMapping(value = "/getUser1")
 public Object getUser(String email, String name) {
   List<User> userList = userDao.findByNameAndEmail(name, email);
   if (null != userList && userList.size() != 0) {
     return userList;
   } else {
     return "没找到符合要求的用户";
   }

}

/**
  * 获取姓名和邮箱是指定内容的用户并排序
  *
  * @return
  */
 @RequestMapping(value = "/getUser2")
 public Object getUser2(String email, String name) {
   List<User> userList = userDao.findByNameAndEmailOrderByIdDesc(name, email);
   if (null != userList && userList.size() != 0) {
     return userList;
   } else {
     return "没找到符合要求的用户";
   }

}

/**
  * 获取姓名和邮箱是指定内容的用户并排序,前两个
  *
  * @return
  */
 @RequestMapping(value = "/getUser3")
 public Object getUser3(String email, String name) {
   List<User> userList = userDao.findTop2ByNameAndEmailOrderByIdDesc(name, email);
   if (null != userList && userList.size() != 0) {
     return userList;
   } else {
     return "没找到符合要求的用户";
   }

}

/**
  * 分页获取邮箱为指定内容的数据
  *
  * @return
  */
 @RequestMapping(value = "/getUser4")
 public Object getUser4(String email, int page) {
   // page 属于下标 从0开始 0代表是第一页
   List<User> userList = userDao.findByEmail(email, new PageRequest(page, 2));
   if (null != userList && userList.size() != 0) {
     return userList;
   } else {
     return "没找到符合要求的用户";
   }

}
}

如此我们就完成了对数据库的操作:

来源：http://blog.csdn.net/u010399316/article/details/53420532