动态SQL片段

对于一些特殊符号，如大于号>、小于号< 等需要写在<![CDATA[]]中方可有效，否则失效。
1、动态SQL片段

通过SQL片段达到代码复用

<!--  动态条件分页查询  --> 
         < sql   id ="sql_count" >  
                select count(*) 
         </ sql >  
         < sql   id ="sql_select" >  
                select * 
         </ sql >  
         < sql   id ="sql_where" >  
                from icp 
                 < dynamic   prepend ="where" >  
                         < isNotEmpty   prepend ="and"   property ="name" >  
                                name like '%$name$%' 
                         </ isNotEmpty >  
                         < isNotEmpty   prepend ="and"   property ="path" >  
                                path like '%path$%' 
                         </ isNotEmpty >  
                         < isNotEmpty   prepend ="and"   property ="area_id" >  
                                area_id = #area_id# 
                         </ isNotEmpty >  
                         < isNotEmpty   prepend ="and"   property ="hided" >  
                                hided = #hided# 
                         </ isNotEmpty >  
                 </ dynamic >  
                 < dynamic  prepend="" >  
                         < isNotNull   property ="_start" >  
                                 < isNotNull   property ="_size" >  
                                        limit #_start#, #_size# 
                                 </ isNotNull >  
                         </ isNotNull >  
                 </ dynamic >  
         </ sql >  
         < select   id ="findByParamsForCount"   parameterClass ="map"   resultClass ="int" >  
                 < include   refid ="sql_count" />  
                 < include   refid ="sql_where" />  
         </ select >  
         < select   id ="findByParams"   parameterClass ="map"   resultMap ="icp.result_base" >  
                 < include   refid ="sql_select" />  
                 < include   refid ="sql_where" />  

        </select>

2、数字范围查询

所传参数名称是捏造所得，非数据库字段，比如_img_size_ge、_img_size_lt字段

< isNotEmpty   prepend ="and"   property ="_img_size_ge" >  
                                <![CDATA[ 
                                img_size >= #_img_size_ge# 
                        ]]> 
                         </ isNotEmpty >  
                         < isNotEmpty   prepend ="and"   property ="_img_size_lt" >  
                                <![CDATA[ 
                                img_size  <  #_img_size_lt# 
                        ]] >  
                         </ isNotEmpty >  

多次使用一个参数也是允许的

 <isNotEmpty prepend="and" property="_now"> 
                                <![CDATA[ 
                                            execplantime >= #_now# 
                                     ]]> 
                        </isNotEmpty> 
                        <isNotEmpty prepend="and" property="_now"> 
                                <![CDATA[ 
                                            closeplantime <= #_now# 
                                     ]]> 
                        </isNotEmpty>

3、时间范围查询

<isNotEmpty prepend="" property="_starttime"> 
                                <isNotEmpty prepend="and" property="_endtime"> 
                                        <![CDATA[ 
                                        createtime >= #_starttime# 
                                        and createtime < #_endtime# 
                                 ]]> 
                                </isNotEmpty> 
                        </isNotEmpty> 

4、in查询

<isNotEmpty prepend="and" property="_in_state"> 
                                state in ('$_in_state$') 
                        </isNotEmpty>

5、like查询

<isNotEmpty prepend="and" property="chnameone"> 
                                (chnameone like '%$chnameone$%' or spellinitial like '%$chnameone$%') 
                        </isNotEmpty> 
                        <isNotEmpty prepend="and" property="chnametwo"> 
                                chnametwo like '%$chnametwo$%' 
                        </isNotEmpty> 

6、or条件

<isEqual prepend="and" property="_exeable" compareValue="N"> 
                                <![CDATA[ 
                                (t.finished='11'    or t.failure=3) 
                        ]]> 
                        </isEqual>

<isEqual prepend="and" property="_exeable" compareValue="Y"> 
                                <![CDATA[ 
                                t.finished in ('10','19') and t.failure<3 
                        ]]> 
                        </isEqual>

7、where子查询

<isNotEmpty prepend="" property="exprogramcode"> 
                                <isNotEmpty prepend="" property="isRational"> 
                                        <isEqual prepend="and" property="isRational" compareValue="N"> 
                                                code not in 
                                                (select t.contentcode 
                                                from cms_ccm_programcontent t 
                                                where t.contenttype='MZNRLX_MA' 
                                                and t.programcode = #exprogramcode#) 
                                        </isEqual> 
                                </isNotEmpty> 
                        </isNotEmpty>

<select id="findByProgramcode" parameterClass="string" resultMap="cms_ccm_material.result"> 
                select * 
                from cms_ccm_material 
                where code in 
                (select t.contentcode 
                from cms_ccm_programcontent t 
                where t.contenttype = 'MZNRLX_MA' 
                and programcode = #value#) 
                order by updatetime desc 
        </select>

9、函数的使用

<!-- 添加 --> 
        <insert id="insert" parameterClass="RuleMaster"> 
                insert into rulemaster( 
                name, 
                createtime, 
                updatetime, 
                remark 
                ) values ( 
                #name#, 
                now(), 
                now(), 
                #remark# 
                ) 
                <selectKey keyProperty="id" resultClass="long"> 
                        select LAST_INSERT_ID() 
                </selectKey> 
        </insert> 
        <!-- 更新 --> 
        <update id="update" parameterClass="RuleMaster"> 
                update rulemaster set 
                name = #name#, 
                updatetime = now(), 
                remark = #remark# 
                where id = #id# 
        </update>

10、map结果集 

<!-- 动态条件分页查询 --> 
        <sql id="sql_count"> 
                select count(a.*) 
        </sql> 
        <sql id="sql_select"> 
                select a.id                vid, 
                a.img             imgurl, 
                a.img_s         imgfile, 
                b.vfilename vfilename, 
    b.name            name, 
                c.id                sid, 
                c.url             url, 
                c.filename    filename, 
                c.status        status 
        </sql> 
        <sql id="sql_where"> 
                From secfiles c, juji b, videoinfo a 
                where 
                a.id = b. videoid 
                and b.id = c.segmentid 
                and c.status = 0 
                order by a.id asc,b.id asc,c.sortnum asc 
                <dynamic prepend=""> 
                        <isNotNull property="_start"> 
                                <isNotNull property="_size"> 
                                        limit #_start#, #_size# 
                                </isNotNull> 
                        </isNotNull> 
                </dynamic> 
        </sql> 
        <!-- 返回没有下载的记录总数 --> 
        <select id="getUndownFilesForCount" parameterClass="map" resultClass="int"> 
                <include refid="sql_count"/> 
                <include refid="sql_where"/> 
        </select> 
        <!-- 返回没有下载的记录 --> 
        <select id="getUndownFiles" parameterClass="map" resultClass="Java.util.HashMap"> 
                <include refid="sql_select"/> 
                <include refid="sql_where"/> 
        </select>