如何在 MyBatis 中使用带注解的动态 SQL 查询(如何使用 selectProvider)?

问题描述

我试图避免在 mybatis3 中使用额外的 xml 来定义映射器.注释正好适合.

I am trying to avoid having an additional xml to define the mapper in mybatis3. Annotation fits right in.

我对@SelectProvider/@InsertProvider/etc 的用法有点困惑.不要以为网上有很多资源可以指导我.

I am a bit confused by the usage of @SelectProvider/@InsertProvider/etc. Don't think there are many resources online guiding me through this.

基本上，我想在mybatis3中找到alternative for的注解版本.

Basically, I will like to find the annotation version of alternative for in mybatis3.

例如，我有一个 xml 映射器，我想将其转换为使用注释

For example, I have a xml mapper and I wanna convert it to use annotation

<select ...>
  <where>
    <if cause.....>
    </if>
    <if cause......>
    </if>
  </where>
</select>

谁能提供包括代码在内的具体答案/解决方案?

Could anyone provide a concrete answer/solution including the code?

提前致谢！

推荐答案

您的替代解决方案可能是:

An alternative solution for you could be:

在@annotation 的开头添加 <script>

Add <script> at the beginning of your @annotation

@Update("<script>
  update Author
    <set>
      <if test="username != null">username=#{username},</if>
      <if test="password != null">password=#{password},</if>
      <if test="email != null">email=#{email},</if>
      <if test="bio != null">bio=#{bio}</if>
    </set>
  where id=#{id}
</script>")

另外，我们在项目中将 .groovy 编译为 .class，因此，我们可以像上面一样在@annotation 中编写 SQL

In additional, we compile .groovy to .class in our projects, thus, we can write SQL in @annotation like above

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