solr做delta-import生成索引总是无效 ：报错

我用delta-import生成索引总是无效，请赐教，db-config如下：

<document name="appinfo">

        <entity name="appentity" pk="id" 
            query="select id,appid, appname, intro from appstore_souapp_threepart_app"
            deltaImportQuery="select id,appid, appname, intro  from appstore_souapp_threepart_app where id ='${appentity.id}'">
            <field column="id" name="id" />
            <field column="appid" name="appid" />
            <field column="appname" name="appname" />
            <field column="intro" name="intro" />
        </entity>
    </document>