Spring Boot Mysql 数据库操作示例

程序员文章站 2024-03-05 16:00:49

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

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:

Spring Boot Mysql 数据库操作示例

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