--删除题库（TABLE_Q ）中，标题（TITLE ）和类型（TYPE ）都相同的数据，仅保留ID最小的一条

DELETE TABLE_Q

FROM

    TABLE_Q,

    ( SELECT MIN( ID ) ID, TITLE, TYPE FROM TABLE_Q GROUP BY TITLE, TYPE HAVING COUNT( * ) > 1 ) T2

WHERE

    TABLE_Q.TITLE = T2.TITLE

    AND OTC_QUESTION_BANK.TYPE = T2.TYPE

    AND OTC_QUESTION_BANK.QUEST_NO > T2.QUEST_NO;