User-defined functions are repeatedly called on the same page to obtain the same value.

When a user-defined function is called multiple times on the same page and the same value is obtained, a user-defined function pici () is used to obtain the value of the pi field under a sequential number, then + 1 (when there is no record for this serial number, the value is 0 + 1 = 1) and then insert several records into the database in sequence, in the form of: & nbsp; & the nbs calls the user-defined function multiple times on the same page and obtains the same value.
I have customized a function pici (). its function is to get the value of the pi field under a serial number, and then add 1 (when there is no record of this serial number, value 0 + 1 = 1)

Insert several records into the database in sequence, in the form:
Serial number pi product components
1 door cover ..
1 2 door fan ..
1 3 lines ..
2 1 door cover ..
2 2 door fans ..
2 3 lines ..


However, when calling a page in PHP, the database should be retrieved every time, and the values obtained are 1, 2, 3 ...... In this way, however, the obtained values are all 1

Some code is attached below. please answer your question. Thank you








Here is the custom function pici ()

Function pici (){
$ SQL = "select ifnull (max (pi) + 1, '1') pi from bill where produce_no = 'submit '";
$ Query = mysql_query ($ SQL );
$ Rs = mysql_fetch_array ($ query );
$ Svc = $ rs [pi];
Return $ svc;
}

The following describes how to call pici () and insert three pieces of data into the database.

// Door parameter
Mysql_query ("insert into bill (color, series, produce_no, pi, prod_type, stuff_id, z, val, amount, typein) values ('$ _ GET [color]', '$ _ GET [series]', '$ produce_no ','". pici (). "',' $ prod_type ',' $ norms_stuff_id ', 'fan model', '$ _ GET [model_1]', '$ men_shu ', '$ _ SESSION [login_id]') ");
// Door cover parameters
Mysql_query ("insert into bill (color, produce_no, prod_type, pi, stuff_id, z, val, amount, typein) values ('$ _ GET [color2]', '$ produce_no', '$ prod_type ','". pici (). "', '2', 'door cover length',' $ mentaochang_shu ',' $ mentao_shu_2 ',' $ _ SESSION [login_id] ')");
// Line specification
Mysql_query ("insert into bill (color, produce_no, prod_type, pi, stuff_id, z, val, amount, typein) values ('$ _ GET [color3]', '$ produce_no', '$ prod_type ','". pici (). "', '3', 'line size',' $ _ GET [norms_3] ',' $ xiantiao_shu ',' $ _ SESSION [login_id] ')");

------ Solution --------------------
At last, this post was edited by xuzuning at 16:29:00 on. how can I publish another post? More?

I understand this.
Serial number pi product part produce_no
1 door cover ..
1 2 door fan ..
1 null line... pre-submitted
Then
1 3 lines ..
This process, right?
------ Solution --------------------
Or the ifnull (max (pi) + 1, '1') problem
Think about it:
If max (pi) is null because it is "pre-submitted", pi has no value
So what is null + 1 equal?
If the value is null, '1' is returned'
If the value is 1, 1 is returned.
Is that true?

If you want to increase pi, you should count the number of non-pre-submitted records Plus 1
------ Solution --------------------
You have where 1 = 2
What makes it strange to get results?


Ask your colleagues and they will tell you where you are wrong.