如何添加一个新行,将列数作为序列号计数

Question

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

行.它应该从1开始,每行增加1.

Answer 1

如果您在SELECT语句中表示:

说你的选择是

select * from tbl

它成为了

select @n := @n + 1 RowNumber, t.*
from (select @n:=0) initvars, tbl t

笔记:

1. select @n:=0 用于将全局变量重置为0
2. @n := @n + 1 从1开始,每行增加1.此列名为"RowNumber"

Answer 2

mySerial向表中添加一个新列,myTable并将每行递增1(从'1'开始):

ALTER TABLE myTable ADD mySerial int(11) DEFAULT '0' NOT NULL;
SELECT @n:=0;
UPDATE myTable SET mySerial = @n := @n + 1;