Paging duplication of data

Some time ago, the test to a bug, the front end of the first display and second pages of data duplication, but also the background debug test. The sql console to print a test run about visualization tools, the problem is still there.

Then remove the page and found that there is no problem. There is a problem in that page. Later consult our company chiefs. He said it might be because you have duplicate field values ​​that situation, plus the best that can guarantee the uniqueness of the field to sort the data.

Before did not change the sql

select * from(
        select
        <include refid="Base_Column_List"/>,
        case
        when TRAIN_STATUS=1
        then '1'
        when TRAIN_STATUS=2
        then '2'
        when TRAIN_STATUS=3
        then '3'
        when TRAIN_STATUS=5
        then '5'
        when (to_char(TRAIN_START_DATE, 'yyyy-mm-dd') || TRAIN_START_TIME) >
        to_char(sysdate, 'yyyy-mm-ddHH24:mi')
        then '4-1'
        when (to_char(TRAIN_END_DATE, 'yyyy-mm-dd') || TRAIN_END_TIME) >
        to_char(sysdate, 'yyyy-mm-ddHH24:mi')
        then '4-2'
        else '4-3'
        end as STATUS
        from TB_TRAINING_INFO
        order by
        case
        when STATUS='1'
        then 1
        when STATUS='3'
        then 2
        when STATUS='4-1'
        then 3
        when STATUS='4-2'
        then 4
        when STATUS='4-3'
        then 5
        when STATUS='2'
        then 6
        else 7
        end asc
        )
        <where>
            <if test="trainName!=null and trainName!=''">
                and TRAIN_NAME like '%' || #{trainName,jdbcType=OTHER} ||'%'
            </if>
            <if test="originatorName!=null and originatorName!=''">
                and ORIGINATOR_NAME like '%' || #{originatorName,jdbcType=OTHER} || '%'
            </if>
            <if test="originatorOrgName!=null and originatorOrgName!=''">
                and ORIGINATOR_ORG_NAME like '%' || #{originatorOrgName,jdbcType=OTHER} || '%'
            </if>
            <if test="trainStatus!= andNull  trainStatus!=''">
                and TRAIN_STATUS = #{trainStatus,jdbcType=CHAR}
            </if>
            <if test="originator!=null and originator!=''">
                and ORIGINATOR = #{originator,jdbcType=OTHER}
            </if>
            <if test="status!=null and status!=''">
                and STATUS = #{status,jdbcType=OTHER}
            </if>
            and delete_flag='0'
        </where>

His status to get value from the sql above is repeated, and then I add a field to solve the problem. Attach modify sql

select * from(
        select
        <include refid="Base_Column_List"/>,
        case
        when TRAIN_STATUS=1
        then '1'
        when TRAIN_STATUS=2
        then '2'
        when TRAIN_STATUS=3
        then '3'
        when TRAIN_STATUS=5
        then '5'
        when (to_char(TRAIN_START_DATE, 'yyyy-mm-dd') || TRAIN_START_TIME) >
        to_char(sysdate, 'yyyy-mm-ddHH24:mi')
        then '4-1'
        when (to_char(TRAIN_END_DATE, 'yyyy-mm-dd') || TRAIN_END_TIME) >
        to_char(sysdate, 'yyyy-mm-ddHH24:mi')
        then '4-2'
        else '4-3'
        end as STATUS
        from TB_TRAINING_INFO
        order by
        case
        when STATUS='1'
        then 1
        when STATUS='3'
        then 2
        when STATUS='4-1'
        then 3
        when STATUS='4-2'
        then 4
        when STATUS='4-3'
        then 5
        when STATUS='2'
        then 6
        else 7
        end asc,UPDATE_DATE desc
        )
        <where>
            <if test="trainName!=null and trainName!=''">
                and TRAIN_NAME like '%' || #{trainName,jdbcType=OTHER} ||'%'
            </if>
            <if test="originatorName!=null and originatorName!=''">
                and ORIGINATOR_NAME like '%' || #{originatorName,jdbcType=OTHER} || '%'
            </if>
            <if test="originatorOrgName!=null and originatorOrgName!=''">
                and ORIGINATOR_ORG_NAME like '%' || #{originatorOrgName,jdbcType=OTHER} || '%'
            </if>
            <if test="trainStatus!=null and trainStatus!=''">
                and TRAIN_STATUS = #{trainStatus,jdbcType=CHAR}
            </if>
            <if test="originator!=null and originator!=''">
                and ORIGINATOR = #{originator,jdbcType=OTHER}
            </if>
            <if test="status!=null and status!=''">
                and STATUS = #{status,jdbcType=OTHER}
            </if>
            and delete_flag='0'
        </where>

Summary: order by the time the last goal on the basis of the sort field should be added that can guarantee the uniqueness of the field to sort the data