对比 MyBatis，你看出什么端倪？

项目地址： https://github.com/braisdom/ObjectiveSql

1 简单查询

@DomainModel
public class Blog {
    private Long id;
    private String title;
    private Integer state;
    @Relation(relationType = RelationType.BELONGS_TO)
    private Author author;
}

根据单字段查询

MyBatis

ObjectiveSQL

public interface BlogMapper {
  @Select("SELECT * FROM blog WHERE id = #{id}")
  Blog selectBlog(int id);
}
...
BlogMapper mapper = session.getMapper(BlogMapper.class); 
Blog blog = mapper.selectBlog(i);

Blog blog = Blog.queryByPrimaryKey(1);

稍微复杂一点的查询

MyBatis

ObjectiveSQL

<?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="org.mybatis.example.BlogMapper">
  <select id="findByTitle" resultType="Blog">
    select * from Blog where title like  '%#{title}%'
  </select>
</mapper>
...
BlogMapper mapper = session.getMapper(BlogMapper.class); 
Blog blog = mapper.findByTitle("标题");

public static Blog queryByTitle(String title) {
     Query<Blog> query = createQuery();
     query.where("title like ?",  "%" + title + "%");
     return query.queryFirst();
}
...
Blog blog = Blog.queryByTitle(1);

2 复杂查询

动态查询

MyBatis

ObjectiveSQL

<select id="findActiveBlogLike"
     resultType="Blog">
  SELECT * FROM BLOG
  WHERE
  <if test="state != null">
    state > #{state}
  </if>
  <if test="title != null">
    AND title like #{title}
  </if>
  <if test="author != null and author.name != null">
    AND author_name like #{author.name}
  </if>
</select>
...
BlogMapper mapper = session.getMapper(BlogMapper.class); 
Blog blog = mapper.findActiveBlogLike(...);

Blog.Table blog = Blog.asTable();
Select select = new Select();
LogicalExpression eternalExpression = new EternalExpression();
if(state != null)
     eternalExpression = eternalExpression.and(blog.state > state);
if(title != null)
     eternalExpression = eternalExpression.and(blog.title.like(title));
if(author != null && author.name != null)
     eternalExpression = eternalExpression.and(blog.author.like(author.name));
return select.from(blog).where(eternalExpression).execute();

关联查询

MyBatis

ObjectiveSQL

<mapper>
  <resultMap type="Blog" id="blog">
    <id column="id" property="id" />
    ...
    <association property="author" javaType="Author">
      ...
    </association>
  </resultMap>
  <select id="findBlog" parameterType="int" resultMap="blog">
    ...
  </select>
</mapper>
...
BlogMapper mapper = session.getMapper(BlogMapper.class); 
Blog blog = mapper. findBlog(...);

Blog blog = Blog.queryByPrimaryKey(1, 
                    Blog.BELONGS_TO_AUTHOR)

NeinChn

2020-12-12 18:10:47 +08:00

这不就是简单场景没必要，复杂场景学习成本高么

举个例子，我们线上数据库都是同一套，因此要做线上隔离全靠表名区别

以 members 为例，staging 环境的表名是 members_staging

你这个文档写的真的不清不楚，根本没办法通过文档决定怎么开发

简单看了下代码，DomainModel 的 tableName 或者 class 的 getSimpleName 。

那我一个 domain 用在多个表上还要搞 2 个类么？

真的有时间，建议完善下文档，至少做到 MyBatis 的文档水平，再做宣传。

想让别人做什么事情都看源代码解决是不现实的事情，有的是太菜看不懂源代码，有的是太忙没有时间花在读这种代码上。