<mapper?namespace="Message"> ??<resultMap?type="com.ljm.java.entity.Message"?id="MessageResult"> ????<id?column="ID"?jdbcType="INTEGER"?property="id"/> ????<result?column="COMMAND"?jdbcType="VARCHAR"?property="command"/> ????<result?column="DESCRIPTION"?jdbcType="VARCHAR"?property="description"/> ????<result?column="CONTENT"?jdbcType="VARCHAR"?property="content"/> ??</resultMap> ??<select?id="queryMessageList"?parameterType="com.ljm.java.entity.Message"?resultMap="MessageResult"> ????select?ID,COMMAND,DESCRIPTION,CONTENT?from?MESSAGE ????<where> ???? <if?test="command?!=?null?and?!&quot;&quot;.equals(command.trim())"> ???? and?COMMAND?like?'%'?#{command}'%' ????</if> ????<if?test="description?!=?null?and?!&quot;&quot;.equals(description.trim())"> ???? and?DESCRIPTION?like?'%'?#{description}?'%'? ????</if> ????</where> ??</select>