（十三）动态SQL之choose、when、otherwise

类似于java中的switch，多选一

 <select id="selectTeacher" parameterType="teacher" resultType="teacher">
       select * 
         from tb_Teacher
    
         <where>
        
             <choose>
               <when test="id!=null">
                 id=#{id}  
               </when>
               
                  
               <when test="name!=null &amp;&amp; name.trim()!=''">
                 name=#{name} 
               </when>
               
               <otherwise>
                  email="tea1@qq.com"
               </otherwise>
             </choose>
         </where>
    </select>