spring中@param和mybatis中@param使用区别

1. spring中@param

<code class="hljs java has-numbering">    <span class="hljs-javadoc">/**
      * 查询指定用户和企业关联有没有配置角色
      *<span class="hljs-javadoctag"> @param</span> businessId  memberId
      *<span class="hljs-javadoctag"> @return</span>
      */</span>
     <span class="hljs-keyword">int</span> selectRoleCount(<span class="hljs-annotation">@Param</span>(<span class="hljs-string">"businessId"</span>) Integer businessId,<span class="hljs-annotation">@Param</span>(<span class="hljs-string">"memberId"</span>) Long memberId); </code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li></ul>

1. mybatis中的param

<code class="hljs java has-numbering">    <span class="hljs-javadoc">/**
      * 查询指定用户和企业关联有没有配置角色
      *<span class="hljs-javadoctag"> @param</span> businessId memberId
      *<span class="hljs-javadoctag"> @return</span>
      */</span>
     <span class="hljs-keyword">int</span> selectRoleCount(<span class="hljs-annotation">@Param</span>(<span class="hljs-string">"businessId"</span>) Integer businessId,<span class="hljs-annotation">@Param</span>(<span class="hljs-string">"memberId"</span>) Long memberId); </code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li></ul>

从表面上看，两种并没有区别，但是在xml文件中使用的时候是有区别的，Spring中的@param在xml需要如下这样引用变量

<code class="hljs vbnet has-numbering"><<span class="hljs-keyword">select</span> id=<span class="hljs-string">"selectRoleCount"</span> resultType=<span class="hljs-string">"java.lang.Integer"</span> >
<span class="hljs-keyword">select</span> 
    count(tbm.id)
    <span class="hljs-keyword">from</span> t_business_member_relation tbm
    <span class="hljs-keyword">where</span> tbm.business_id = <span class="hljs-preprocessor">#{0,jdbcType=INTEGER}</span>
    <span class="hljs-keyword">and</span> tbm.member_id = <span class="hljs-preprocessor">#{1,jdbcType=INTEGER}</span>
    <span class="hljs-keyword">and</span> tbm.role_business_id <span class="hljs-keyword">is</span> <span class="hljs-keyword">not</span> null
</<span class="hljs-keyword">select</span>></code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li></ul>

是根据参数的顺序来取值的，并且从0开始。而在mybatis @param在xml中则是如下这样引用变量的

<code class="hljs vbnet has-numbering"><<span class="hljs-keyword">select</span> id=<span class="hljs-string">"selectRoleCount"</span> resultType=<span class="hljs-string">"java.lang.Integer"</span> >
    <span class="hljs-keyword">select</span> 
    count(tbm.id)
    <span class="hljs-keyword">from</span> t_business_member_relation tbm
    <span class="hljs-keyword">where</span> tbm.business_id = <span class="hljs-preprocessor">#{businessId,jdbcType=INTEGER}</span>
    <span class="hljs-keyword">and</span> tbm.member_id = <span class="hljs-preprocessor">#{memberId,jdbcType=INTEGER}</span>
    <span class="hljs-keyword">and</span> tbm.role_business_id <span class="hljs-keyword">is</span> <span class="hljs-keyword">not</span> null
 </<span class="hljs-keyword">select</span>></code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li></ul>

是通过参数名来引用的
注：如果Mapper.java文件中引用的是Spring的

<code class="hljs avrasm has-numbering">org<span class="hljs-preprocessor">.springframework</span><span class="hljs-preprocessor">.data</span><span class="hljs-preprocessor">.repository</span><span class="hljs-preprocessor">.query</span><span class="hljs-preprocessor">.Param</span><span class="hljs-comment">;</span></code><ul style="display: block;" class="pre-numbering"><li>1</li></ul>

但是Mapper.xml中使用的是mybatis 的用法，那么就会如下的错误

<code class="hljs oxygene has-numbering">org.mybatis.spring.MyBatisSystemException: <span class="hljs-keyword">nested</span> exception <span class="hljs-keyword">is</span> org.apache.ibatis.binding.BindingException: Parameter <span class="hljs-string">'businessId'</span> <span class="hljs-keyword">not</span> found. Available parameters are [<span class="hljs-number">1</span>, <span class="hljs-number">0</span>, param1, param2]</code><ul style="display: block;" class="pre-numbering"><li>1</li></ul>

截图如下

所以在使用的时候一定要注意@param引用和使用的一致性