Re: How to retrieve the position of a row inside a table with garbage data in all cloumns?

From: Date: Tue, 23 Sep 2008 04:50:59 +0000
Subject: Re: How to retrieve the position of a row inside a table with garbage data in all cloumns?
References: 1 2 3  Groups: php.db 
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As a caution, I would never, ever use a query that relies on the data to be returned from the table in a certain order. That is just wrong and goes against the principals of a rdbms. Just write your queries in such a way that the result is always returned the way you want it regardless of the way it is ordered in the table. Jack 2008/9/23 Trullo <analpaper@gmail.com> > En/na Chris ha escrit: > > Trullo wrote: > >> hello_world(); > >> > >> in fact.. how to goTo next/previous row of a table without using > >> incremental ids AND without reading the whole table? > >> i will explain: > >> I wanna do something like a paging toolbar blinded to a list of rows > >> (for example, a literally view of a db table). > >> The first difference from a normal paging system, is that i wanna show > >> only one row per page, and luckily i know the id of that first viewed > >> row; so, no problem until here. Im able to show the first row xD. > >> The second difference is that i don't know the position of the first > >> viewed row inside the whole original table, only the id of the row > >> (maybe someone is laughing while reading 'only'). > >> > >> I would like to know the position of that row to allow a easy goTo > >> next/prev method using LIMIT/OFFSET sql clauses. > > > > Assuming the row id you have is a primary key, you could do: > > > > select * from table where primary_key > $current_rowid order by > > primary_key asc limit 1; > > > > > > For previous you could do: > > > > select * from table where primary_key < $current_rowid order by > > primary_key desc limit 1; > > > Lot of thanks! its true that i dont care about the position of row. Your > solution will do the work sure :o] > > As a curiosity... then.. the only way to know the position of a row, is > read the whole table? > > -- > PHP Database Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- J.A. van Zanen

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