mybatis操作数据库(以postgre数据库为例)

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使用mybatis操作数据库(以postgre数据库为例)

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以springboot项目为基础，所以首先创建springboot项目
pom.xml – (导入相关依赖)

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.0.1.RELEASEversion>
        <relativePath/> 
    parent>
    <groupId>com.examplegroupId>
    <artifactId>mybatis-demoartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>mybatis-demoname>
    <description>Demo project for mybatisdescription>
    <properties>
        <java.version>1.8java.version>
    properties>
    <dependencies>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.postgresqlgroupId>
            <artifactId>postgresqlartifactId>
            <scope>runtimescope>
        dependency>

        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>2.2.0version>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>

        
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <version>1.18.12version>
            <scope>providedscope>
        dependency>

    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>
project>

application.yml – (添加配置)

spring:
  datasource:
    driver-class-name: org.postgresql.Driver
    url: jdbc:postgresql://localhost:5432/postgres
    username: postgres
    password: 1234
#配置mybatis映射文件的路径
mybatis:
  mapper-locations: classpath*:/mapper/*.xml

server:
  port: 8081

TUserMapper.java – (创建mybatis映射接口)

package com.example.mybatis.mapper;
import com.example.mybatis.domain.TUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;

@Mapper
public interface TUserMapper{
    List<TUser> findAll();

    void insert(@Param("user")TUser user);
}

TUserMapper.xml – (在resource包mapper包下创建映射文件)

DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mybatis.mapper.TUserMapper">

    
    <resultMap id="BaseResultMap" type="com.example.mybatis.domain.TUser">
        <id column="id" property="id" />
        <result column="nick_name" property="nickName" />
        <result column="company_name" property="companyName" />
        <result column="company_id" property="companyId" />
    resultMap>

    <select id="findAll" resultMap="BaseResultMap">
        select * from t_user;
    select>

    <insert id="insert" parameterType="com.example.mybatis.domain.TUser">
        insert into t_user(id,name,nick_name,company_name,company_id,password,status)values (
            #{user.id},
            #{user.name,jdbcType=VARCHAR},
            #{user.nickName,jdbcType=VARCHAR},
            #{user.companyName,jdbcType=VARCHAR},
            #{user.companyId,jdbcType=VARCHAR},
            #{user.password,jdbcType=VARCHAR},
            '0'
        )
    insert>
mapper>

TUser.java – (针对要操作的表创建对应的实体类)

package com.example.mybatis.domain;

import lombok.Data;

/**
 * @Classname TUser
 * @Description TODO
 * @Date 2021/11/2 10:53
 * @Created by wang
 */
@Data
public class TUser {
    private Integer id;
    private String name;
    private String nickName;
    private String companyName;
    private String companyId;
    private String password;
    private String status;
}

UserController.java – (创建Controller，引入对应的mapper，对外提供接口)

package com.example.mybatis.controller;

import com.example.mybatis.domain.TUser;
import com.example.mybatis.mapper.TUserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * @Classname UserController
 * @Description TODO
 * @Date 2021/11/2 11:19
 * @Created by wang
 */
@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private TUserMapper tUserMapper;

    @RequestMapping("/findAll")
    public List<TUser> findAll(){
        return tUserMapper.findAll();
    }
    @RequestMapping("/insert")
    public ResponseEntity<Void> insert(@RequestBody TUser user){
        tUserMapper.insert(user);
        return ResponseEntity.status(HttpStatus.CREATED).build();
    }
}