采用伪列 rownum
查询前10条记录
select * from t_user t where ROWNUM <10;
按照学生ID排名,抓取前三条记录
SELECT * FROM(SELECT id,realname FROM T_USER ORDER BY id asc ) WHERE ROWNUM <=3
分页SQL写法,从第10条记录开始,提取10条记录。
SELECT * FROM (SELECT ROWNUM rn,id,realname FROM (SELECT id,realname FROM T_USER)WHERE ROWNUM<=20) t2 WHERE T2.rn >=10;
按照学生ID排名,从第10条记录开始,提取10条记录。
SELECT * FROM (SELECT ROWNUM rn,id,realname FROM (SELECT id,realname FROM T_USER ORDER BY id asc)WHERE ROWNUM<=20) t2 WHERE T2.rn >=10;
【注】
1. where rownum>1 不能抓取到记录。
2. where rownum between 2 and 10 也不能抓取到记录。
运用分析函数
用分析函数row_number()over(ORDER BY 字段)
按照学生ID排名,抓取前三条记录
SELECT * FROM(SELECT id,realname,row_number()over(ORDER BY id asc) rn FROM T_USER)WHERE rn <=3
按照学生ID排名,从第10条记录开始,提取10条记录。
SELECT * FROM(SELECT id,realname,row_number()over(ORDER BY id asc) rn FROM T_USER)WHERE rn BETWEEN 10 AND 20
运用minus方法
从第10条记录开始,提取10条记录。
SELECT * FROM T_USER WHERE ROWNUM<20 MINUS SELECT * FROM T_USER WHERE ROWNUM<10;
按ID排序后,从第10条记录开始,提取10条记录。
(SELECT * FROM (SELECT * FROM T_USER ORDER BY id asc) WHERE ROWNUM<20) MINUS( SELECT * FROM (SELECT * FROM T_USER ORDER BY id asc) WHERE ROWNUM<10);