如何在sqlite IPHONE中获取rowNum之类的列

问题描述

我有一个这样的 Sqlite 数据库表(没有升序)

I have an Sqlite database table like this (with out ascending)

但是我需要以按名称升序检索表，当我将其设置为升序时，rowId 会以混乱的顺序更改如下

But i need to retrive the table in Ascending order by name, when i set it ascending order the rowId changes as follows in jumbled order

但我每次都需要按升序检索一些数量有限的联系人 5

But i need to retrieve some limited number of contacts 5 in ascending order every time

喜欢Aaa - Eeee 和 然后是 Ffff- Jjjjj ......

like Aaa - Eeee and then Ffff- Jjjjj ......

但是要设置 **t 限制，例如 0-5 5-10 .... ** 它可以使用 rowids，因为它们处于混乱的顺序

but to se**t limits like 0-5 5-10 .... ** it can able using rowids since they are in jumble order

所以我需要另一列，如(oracle中的rowNum)，其顺序为1234567...每次如下

如何使用现有列检索该列

how to retrive that column with existing columns

注意:我们在 SQLITE 中没有 ROWNUM LIKE COLUMN

推荐答案

这是一种伪造 RowNum 的方法，希望能帮到你:

This is a way of faking a RowNum, hope it helps:

SELECT 
   (SELECT COUNT(*)
    FROM Names AS t2
    WHERE t2.name < t1.name
   ) + (
      SELECT COUNT(*) 
      FROM Names AS t3 
      WHERE t3.name = t1.name AND t3.id < t1.id
   ) AS rowNum,
   id,
   name
FROM Names t1
ORDER BY t1.name ASC

SQL Fiddle 示例

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