课时18：trim标签与MyBatis内置参数

<!--查询操作处理-->
<select id="queryStudentByNoWithONGL" resultType="Student" parameterType="student">
        select * from student
        <trim prefix="where" prefixOverrides="and|or">
            <if test="stuName!=null and stuName!=‘‘">and stuName like ‘%${stuName}%‘</if>
            <if test="graName!=null and graName!=‘‘">and graName like ‘%${graName}%‘</if>
            <if test="stuAge!=null and stuAge!=‘‘">and stuAge = #{stuAge} </if>
        </trim>
    </select>
<!--修改操作处理-->
<update id="updateSmbmsProviderByIdTrim" parameterType="SmbmsProvider">
        update smbms_provider
        <trim prefix="set" suffix="where id=#{id}" suffixOverrides=",">
        <if test="proCode!=null and proCode!=‘‘">proCode=#{proCode},</if>
        <if test="proName!=null and proName!=‘‘">proName=#{proName},</if>
        <if test="proDesc!=null and proDesc!=‘‘">proDesc=#{proDesc},</if>
        <if test="proContact!=null and proContact!=‘‘">proContact=#{proContact},</if>
        <if test="proPhone!=null and proPhone!=‘‘">proPhone=#{proPhone},</if>
        <if test="proAddress!=null and proAddress!=‘‘">proAddress=#{proAddress},</if>
        <if test="proFax!=null and proFax!=‘‘">proFax=#{proFax},</if>
        <if test="createdBy!=null">createdBy=#{createdBy},</if>
        <if test="creationDate!=null">creationDate=#{creationDate},</if>
        <if test="modifyDate!=null">modifyDate=#{modifyDate},</if>
        <if test="modifyBy!=null">modifyBy=#{modifyBy},</if>
        </trim>
    </update>

<select id="queryStudentByNoWithONGL" resultType="Student" parameterType="student">
        select * from student
        <trim prefix="where" prefixOverrides="and|or">
            <if test="stuName!=null and stuName!=‘‘">and stuName like ‘%${_parameter.stuName}%‘</if>
            <if test="graName!=null and graName!=‘‘">and graName like ‘%${graName}%‘</if>
            <if test="stuAge!=null and stuAge!=‘‘">and stuAge = #{stuAge} </if>
        </trim>
    </select>