MySQL SELECT增量计数器 | SELECT增量计数器

本文介绍了MySQL SELECT增量计数器的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

这是我的MySQL查询:

Here is my MySQL query:

SELECT name FROM table;

如何在name旁边选择增量计数器?预期输出:

How can I also select an increment counter alongside name? Expected output:

Jay 1
roy 2
ravi 3
ram 4

推荐答案

select name,
      @rownum := @rownum + 1 as row_number
from your_table
cross join (select @rownum := 0) r
order by name

此部分:

cross join (select @rownum := 0) r

使得可以引入变量而无需单独的查询.因此，第一个查询也可以细分为两个查询，如下所示:

makes it possible to introduce a variable without the need of a seperate query. So the first query could also be broken down into two queries like this:

set @rownum := 0;

select name,
      @rownum := @rownum + 1 as row_number
from your_table
order by name;

例如在存储过程中使用时.

for instance when used in a stored procedure.

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