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

 
 
  4.0.0 
 
  com.imgod 
  testjpa 
  0.0.1-SNAPSHOT 
  war 
 
  TestJpa 
  Demo project for Spring Boot 
 
   
    org.springframework.boot 
    spring-boot-starter-parent 
    1.4.2.RELEASE 
      
   
 
   
    UTF-8 
    UTF-8 
    1.8 
   
 
   
     
      org.springframework.boot 
      spring-boot-starter-data-jpa 
     
     
      org.springframework.boot 
      spring-boot-starter-web 
     
 
     
      org.springframework.boot 
      spring-boot-starter-tomcat 
      provided 
     
     
      org.springframework.boot 
      spring-boot-starter-test 
      test 
     
     
      mysql 
      mysql-connector-java 
     
     
      org.springframework.boot 
      spring-boot-starter-jdbc 
     
     
     
      org.hibernate 
      hibernate-core 
     
   
 
   
     
       
        org.springframework.boot 
        spring-boot-maven-plugin 
       
     
   
 
 
 

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 { 
  //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 findByName(String name);//根据用户名查询 
   
  //select * from test.users where email='[email protected]' and name='imgod'; 
  List findByNameAndEmail(String name,String email);//根据用户名和邮箱进行查询 
   
  //select * from test.users where email='[email protected]' and name='imgod4444' order by id desc; 
  List 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='[email protected]' and name='imgod4444' order by id desc limit 2; 
  List 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 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 list = (List) 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 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 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 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 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:

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。