本文介绍了如何添加一个新列,将行数计算为序列号的处理方法,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
record of
id fare commission routecode vehicle number productcode date time driver owner name
15 12345 123 4533 1 3344 2011-03-18 00:00:00 yasir saleem
20 a a 3433 1 2333 2011-03-25 00:00:00 yasir saleem
36 11111 11111 3433 1 2333 2011-03-25 16:13:12 yasir saleem
9 1233 123 3433 nk-234 2333 2011-03-24 00:00:00 siddiq aslam
21 1200 120 4533 nk-234 7655 2011-03-24 00:00:00 siddiq aslam
22 1200 133333 0987 nk-234 2333 2011-03-11 00:00:00 siddiq aslam
23 10000 11 4533 nk-234 7655 2011-03-19 00:00:00 siddiq aslam
25 122 12 0987 nk-234 2333 2011-03-11 00:00:00 siddiq aslam
26 1000 100 3344 nk-234 7655 2011-03-11 00:00:00 siddiq aslam
27 1000 100 3344 nk-234 2333 2011-03-10 00:00:00 siddiq aslam
34 100 10 3344 nk-234 2333 2011-03-18 00:00:00 siddiq aslam
35 100 10 3344 nk-234 2333 2011-03-02 00:00:00 siddiq aslam
5 1000 100 1234 wq1233 3344 2011-03-10 22:30:00 waqas sami
6 2222 22 1234 wq1233 3344 2011-03-17 22:30:00 waqas sami
24 a a 4533 PSS-1234 7655 2011-03-02 00:00:00 salman salam
42633 145175
我想在 id 之前添加另一列来计算数量
I want to add another column before id which counts the number of
行.它应该从 1 开始,每行增加 1.
rows. It should start from 1 and increment by 1 for each row.
推荐答案
如果您的意思是在 SELECT 语句中:
If you mean in a SELECT statement:
说你的选择是
select * from tbl
变成
select @n := @n + 1 RowNumber, t.*
from (select @n:=0) initvars, tbl t
注意事项:
select @n:=0
用于将全局变量重置为0@n := @n + 1
每行增加 1,从 1 开始.这一列被命名为RowNumber"
select @n:=0
is used to reset the global variable to 0@n := @n + 1
increases it by 1 for each row, starting from 1. This column is named "RowNumber"
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