sql面試題6 zhuan zai

在面試過程當中屢次碰到兩道SQL查詢的題目，一是查詢A(ID,Name)表中第31至40條記錄，ID做爲主鍵多是不是連續增加的列，完整的查詢語句以下：

select  top 10 * from A where ID >(select max(ID) from (select  top 30 ID from A order by ID) as T) order by ID
另一道題目的要求是查詢表A中存在ID重複三次以上的記錄,並顯示工有多少個；完整的查詢語句以下：
select id, Count（*) from A group by id having count(*)>1   個數
select *  from xs where id1 in (select id1 from xs group by id1 having count(*)>2 ) 數據

以上兩道題目很是有表明意義，望各位把本身碰到的有表明的查詢都貼上來。
 分析：一：
1。 select  top 6 ID1 from xs order by ID1    對XS表中的前6行按ID字段進行上升排序。
2。 select max(ID1) from (select  top 6 ID1 from xs order by ID1)as T  查詢排序後的表（6列）的最大ID
3。select  top 4 * from xs where ID1 >(select max(ID1) from (select  top 6 ID1 from xs order by ID1) T) order by ID1   查詢當ID1大於最大ID的前4行的數據
二：
1。select id1 from xs group by id1 having count(*)>2  查詢ID1重複3次的ID的值X
2。select * from xs where ID1 in (select id1 from xs group by id1 having count(*)>2)   查詢ID1=X的數據
3 select  distinct * from xs where id1 in(select id1 from xs group by id1 having count(*)>3) 這樣就能夠祛除重複值了