【SQL】Oracle分页查询的三种方法
采用伪列 rownum
查询前10条记录
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[sql] select * from t_user t where ROWNUM <10;
按照学生ID排名，抓取前三条记录[java] 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。[java] 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。[sql] 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;
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【注】
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where rownum>1
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不能抓取到记录。
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where rownum between 2 and 10
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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)
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按照学生ID排名，抓取前三条记录[sql] 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。[sql] 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。[java] 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。[sql] (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);
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sql = " SELECT * FROM ( SELECT A.*,rownum rn FROM ( SELECT * FROM task ) A WHERE rownum <=" + (pageIndex) * pageSize + " ) WHERE rn>" + (pageIndex - 1) * pageSize + " ORDER BY ADDTIME DESC,OBJECTID DESC";