MySQL SELECT 增量计数器
这是我的 MySQL 查询:
Here is my MySQL query:
SELECT name FROM table;
我怎样才能在 name
旁边选择一个增量计数器?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
这部分:
cross join (select @rownum := 0) r
可以在不需要单独查询的情况下引入变量.所以第一个查询也可以分解成两个这样的查询:
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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