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):

Mybatis增删改查实例

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() {

}

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:

Mybatis增删改查实例

由于不能识别java中的xml文件,所以我们需要在pom.xml中加入:

Mybatis增删改查实例

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:

Mybatis增删改查实例

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:

Mybatis增删改查实例
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:

Mybatis增删改查实例

给出测试类:
Mybatis增删改查实例

以上所述希望对大家有所帮助。