Mybatis实现动态SQL（环境搭建）

• • SQL
  • 第一步：建立实体类
  • • 建立Blog类
  • 第二步：建立Mapper接口
  • • 建立BlogMapper接口
  • 第三步：建立Mapper.XML文件
  • • 建立BlogMapper.XML文件
  • 第四步：在核心配置文件中绑定注册我们的Mapper接口或者文件
  • 第五步：建立工具类：实现UUID
  • 第六步：测试类：插入数据
  • 文件结构：

CREATE TABLE blog(
	id varchar(50) not null comment '博客id',
	title varchar(100) not null comment '博客标题',
	author varchar(30) not null comment '博客作者',
	create_time datetime not null comment '创建时间',
	views int(30) not null comment '浏览量'
)

package org.pojo;

import java.util.Date;

public class Blog {
    private String id;
    private String title;
    private String author;
    private Date createTime;//属性名和字段名不一致
    private int views;

    @Override
    public String toString() {
        return "Blog{" +
                "id='" + id + ''' +
                ", title='" + title + ''' +
                ", author='" + author + ''' +
                ", createTime=" + createTime +
                ", views=" + views +
                '}';
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public int getViews() {
        return views;
    }

    public void setViews(int views) {
        this.views = views;
    }
}

package org.dao;

import org.pojo.Blog;

public interface BlogMapper {
    //插入数据

    int addBlog(Blog blog);
}

    
        insert into mybatis.blog (id,title,author,create_time,views) values (#{id},#{title},#{author},#{createTime},#{views})
    

package org.utils;

import java.util.UUID;

@SuppressWarnings("all")//抑制警告
public class IDutils {
    public static String getId(){
        return UUID.randomUUID().toString().replaceAll("-","");
    }
}

import org.apache.ibatis.session.SqlSession;
import org.dao.BlogMapper;
import org.junit.Test;
import org.pojo.Blog;
import org.utils.IDutils;
import org.utils.MybatisUtils;

import java.util.Date;

public class MyTest {
    @Test
    public void addInitBlog(){
        SqlSession sqlSession = null;
        try{
            sqlSession = MybatisUtils.getSqlSession();
            BlogMapper mapper = sqlSession.getMapper(BlogMapper.class);
            Blog blog = new Blog();
            blog.setId(IDutils.getId());
            blog.setTitle("Mybatis如此简单!!!");
            blog.setAuthor("lyh");
            blog.setCreateTime(new Date());
            blog.setViews(9999);

            mapper.addBlog(blog);

            blog.setId(IDutils.getId());
            blog.setTitle("Java如此简单!!!");
            mapper.addBlog(blog);

            blog.setId(IDutils.getId());
            blog.setTitle("MySQL如此简单!!!");
            mapper.addBlog(blog);

            blog.setId(IDutils.getId());
            blog.setTitle("Spring如此简单!!!");
            mapper.addBlog(blog);
            sqlSession.commit();
        }catch(Exception e){
            e.printStackTrace();
        }catch(Error e){
            e.printStackTrace();
        }finally {
            sqlSession.close();
        }
    }
}