Mybatis增删改查实例
这篇文章主要介绍了Mybatis实现对数据的增删改查实例详解,使用开发工具idea。
新建maven项目,导入Mybatis依赖(因为要使用到数据库,所以我们先把数据库连接的依赖也加上,我这里为MySql):
先创建一个实体类:
package com.entity;
import java.io.Serializable;
public class Users implements Serializable{
private int uid;
private String uname;
private String upwd;
public Users() {
}
import java.io.Serializable;
public class Users implements Serializable{
private int uid;
private String uname;
private String upwd;
public Users() {
}
public Users(String uname, String upwd) {
this.uname = uname;
this.upwd = upwd;
}
public Users(int uid, String uname, String upwd) {
this.uid = uid;
this.uname = uname;
this.upwd = upwd;
}
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getUpwd() {
return upwd;
}
public void setUpwd(String upwd) {
this.upwd = upwd;
}
@Override
public String toString() {
return "Users{" +
"uid=" + uid +
", uname='" + uname + '\'' +
", upwd='" + upwd + '\'' +
'}';
}
}
使用MyBatis对数据进行增删改查操作有两种方法,分别为配置文件操作和注解操作。
通过配置文件MyBatis-config.xml进行操作(对数据库信息进行配置):
<?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"> <configuration> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/test"/> <property name="username" value="root"/> <property name="password" value="password"/> </dataSource> </environment> </environments> <mappers> <mapper resource="com/entity/Users.xml"/> </mappers> </configuration>
下面为我的项目结构:
由于不能识别java中的xml文件,所以我们需要在pom.xml中加入:
配置操作数据库语句文件Users.xml,如下所示:
<?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.dao.UsersDao"> <select id="getOne" resultType="com.entity.Users" parameterType="int"> select * from users where uid = #{uid} </select> <select id="getAll" resultType="com.entity.Users"> select * from users </select> <select id="add" parameterType="com.entity.Users"> insert into users(uname,upwd) values(#{uname},#{upwd}) </select> <select id="delete" parameterType="int"> delete from users where uid = #{uid} </select> <select id="update" parameterType="com.entity.Users"> update users set uname=#{uname},upwd=#{upwd} where uid = #{uid} </select> <!--动态sql--> <select id="getUsers" resultType="com.entity.Users" parameterType="com.entity.Users"> select * from users <where> <if test="uname!=null"> uname = #{uname} </if> <if test="upwd!=null"> and upwd = #{upwd} </if> </where> </select> </mapper>
通过配置文件实现对数据库的增删查改基本上已经完成,接下来给出测试类,可以进行测试,如下所示:
通过注解进行操作
通过注解进行操作需要写一个接口,但是不必实现,如下所示:
同时,需要在数据库配置文件中添加所写的接口,在mybatis-config.xml中添加如下语句:
给出测试类:
以上所述希望对大家有所帮助。