数据库分页语句

取出sql表中第3140的记录(以自动增长ID为主键)

sql server方案1

 

    select top 10 * from t where id not in (select top 30 id from t order by id ) orde by id

sql server方案2

    select top 10 * from t where id in (select top 40 id from t order by id) order by id desc

 

mysql方案:select * from t order by id limit 30,10

 

oracle方案:

SELECT * FROM 
(
SELECT A.*, ROWNUM RN 
FROM (SELECT * FROM TABLE_NAME) A 
WHERE ROWNUM <= 40
)
WHERE RN >= 21
 

1.分页技术1(直接利用sql语句进行分页,效率最高和最推荐的)

 

 

mysql:sql = "select * from articles limit " + (pageNo-1)*pageSize + "," + pageSize;

oracle: sql = "select * from " +

                                                        "(select rownum r,* from " +

                                                               "(select * from articles order by postime desc)" +

                                                        "where rownum<= " + pageNo*pageSize +") tmp " +

                                                 "where r>" + (pageNo-1)*pageSize;

注释:第7行保证rownum的顺序是确定的,因为oracle的索引会造成rownum返回不同的值

简洋提示:没有order by时,rownum按顺序输出,一旦有了order byrownum不按顺序输出了,这说明rownum是排序前的编号。如果对order by从句中的字段建立了索引,那么,rownum也是按顺序输出的,因为这时候生成原始的查询结果集时会参照索引表的顺序来构建。

 

sqlserver:sql = "select top 10 * from id not id(select top " + (pageNo-1)*pageSize + "id from articles)"

 

 

 

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