rownum

How to use rownum [duplicate]

由 你说的曾经没有我的故事 提交于 2019-11-27 06:32:48
问题 This question already has answers here : How to get second largest or third largest entry from a table (12 answers) SELECTing top N rows without ROWNUM? (5 answers) Closed 6 years ago . I have a employee table in oracle with name,salary and other details. I am trying to get the second highest salary but not able to fetch. This one working fine with e_salary as (select distinct salary from employee) select salary from e_salary order by salary desc And gives output: 450000 61000 60000 50000

Rownum in postgresql

由 烂漫一生 提交于 2019-11-26 17:35:30
Is there any way to simulate rownum in postgresql ? Postgresql > 8.4 SELECT row_number() OVER (ORDER BY col1) AS i, e.col1, e.col2, ... FROM ... Wolfgang Vollmann I have just tested in Postgres 9.1 a solution which is close to Oracle ROWNUM: select row_number() over() as id, t.* from information_schema.tables t; Postgresql have limit. Oracle's code: select * from tbl where rownum <= 1000; same in Postgresql's code: select * from tbl limit 1000 If you just want a number to come back try this. create temp sequence temp_seq; SELECT inline_v1.ROWNUM,inline_v1.c1 FROM ( select nextval('temp_seq')

SQL ROWNUM how to return rows between a specific range

由 人走茶凉 提交于 2019-11-26 15:22:07
How can I return a specific range of ROWNUM values? I'm trying the following: select * from maps006 where rownum >49 and rownum <101 This returns only rows matching the < operator. SELECT * from ( select m.*, rownum r from maps006 m ) where r > 49 and r < 101 SELECT * FROM ( SELECT q.*, rownum rn FROM ( SELECT * FROM maps006 ORDER BY id ) q ) WHERE rn BETWEEN 50 AND 100 Note the double nested view. ROWNUM is evaluated before ORDER BY , so it is required for correct numbering. If you omit ORDER BY clause, you won't get consistent order. I know this is an old question, however, it is useful to

Oracle: Updating a table column using ROWNUM in conjunction with ORDER BY clause

由 馋奶兔 提交于 2019-11-26 14:07:45
问题 I want to populate a table column with a running integer number, so I'm thinking of using ROWNUM. However, I need to populate it based on the order of other columns, something like ORDER BY column1, column2 . That is, unfortunately, not possible since Oracle does not accept the following statement: UPDATE table_a SET sequence_column = rownum ORDER BY column1, column2; Nor the following statement (an attempt to use WITH clause): WITH tmp AS (SELECT * FROM table_a ORDER BY column1, column2)

Selecting the second row of a table using rownum

由 烂漫一生 提交于 2019-11-26 06:46:39
问题 I have tried the below query: select empno from ( select empno from emp order by sal desc ) where rownum = 2 This is not returning any records. When I tried this query select rownum,empno from ( select empno from emp order by sal desc) It gives me this output: ROWNUM EMPNO 1 7802 2 7809 3 7813 4 7823 Can anyone tell me what\'s the problem with my first query? Why is it not returning any records when I add the ROWNUM filter? 回答1: To explain this behaviour, we need to understand how Oracle

Rownum in postgresql

由 江枫思渺然 提交于 2019-11-26 05:30:06
问题 Is there any way to simulate rownum in postgresql ? 回答1: Postgresql > 8.4 SELECT row_number() OVER (ORDER BY col1) AS i, e.col1, e.col2, ... FROM ... 回答2: I have just tested in Postgres 9.1 a solution which is close to Oracle ROWNUM: select row_number() over() as id, t.* from information_schema.tables t; 回答3: Postgresql have limit. Oracle's code: select * from tbl where rownum <= 1000; same in Postgresql's code: select * from tbl limit 1000 回答4: If you just want a number to come back try this

SQL ROWNUM how to return rows between a specific range

由 蹲街弑〆低调 提交于 2019-11-26 03:57:03
问题 How can I return a specific range of ROWNUM values? I\'m trying the following: select * from maps006 where rownum >49 and rownum <101 This returns only rows matching the < operator. 回答1: SELECT * from ( select m.*, rownum r from maps006 m ) where r > 49 and r < 101 回答2: SELECT * FROM ( SELECT q.*, rownum rn FROM ( SELECT * FROM maps006 ORDER BY id ) q ) WHERE rn BETWEEN 50 AND 100 Note the double nested view. ROWNUM is evaluated before ORDER BY , so it is required for correct numbering. If

How to use Oracle ORDER BY and ROWNUM correctly?

由 你。 提交于 2019-11-26 03:52:46
问题 I am having a hard time converting stored procedures from SQL Server to Oracle to have our product compatible with it. I have queries which returns the most recent record of some tables, based on a timestamp : SQL Server: SELECT TOP 1 * FROM RACEWAY_INPUT_LABO ORDER BY t_stamp DESC => That will returns me the most recent record But Oracle: SELECT * FROM raceway_input_labo WHERE rownum <= 1 ORDER BY t_stamp DESC => That will returns me the oldest record (probably depending on the index),
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