"Tomorrow Graduation design reply, good nervous, beg each road moderator bless"

Source: Internet
Author: User
What I do is a graduation design topic system, now in the familiar code. I know which function is implemented by which code, but I am very vague about the specific meaning of the code. Looking for a master to help me in the next note in the rear ~ ~
Since my project is old based on modifying some of the added features, it is sometimes necessary to add
Extract ($_post);
Or
Extract ($_request);
To run some features, what does that mean?
Also, I have to follow a few sentences behind every code that executes the database.
$query = "SELECT * from $student _table where xuehao= ' $xuehao '"; mysql_query ("Set names ' GB2312 '"); $result =mysql_query ($ query); $row =mysql_fetch_array ($result);

And this is a part of revising the subject, I don't know what SN and ssn are for.
$query = "Select number as sn,surplus as SSN from $keti _table where id= ' $id '";   mysql_query ("Set names ' gb2312 '");   $result =mysql_query ($query); $row =mysql_fetch_array ($result), if ($number 1< $row [' SN ']) {if ($number 1< ($row [' SN ']-$row [' ssn ']) {echo "

the number of people can not be less than the number of selected topics, the number of changes failed! "; echo" "; exit;} else{$query 2=mysql_query ("Update $keti _table set number= ' $newnumber ' where id= ' $id '"); $query 3=mysql_query ("Update $ Keti_table set surplus=surplus-($row [sn]-$newnumber) where id= ' $id ' "); mysql_query (" Set names ' gb2312 ' "); $result 1=mysql_query ($query 3);}} else{$query 4=mysql_query ("Update $keti _table set number= ' $newnumber ' where id= ' $id '"); $query 5=mysql_query ("Update $ Keti_table Set surplus=surplus+ ($newnumber-$row [SN]) where id= ' $id ' "); mysql_query (" Set names ' gb2312 ' "); $result 2=mysql_query ($query 5); }if ($result ==true) {echo "

Modify the project success! "; echo " "; Exit }


This is a piece of code to download the material
$file _name= "related information. rar";  $file _dir= "temp/./";  if (!file_exists ($file _dir. $file _name))  {  echo "

The file could not be found

"; echo " "; Exit; } else{ $file =fopen ($file _dir $file _name, "R");//Open File Header ("Content-type:application/octet-stream"); Header ("Accept-ranges:bytes"); Header ("Accept-length:". FileSize ($file _dir. $file _name)); Header ("content-disposition:attachment; Filename= ". $file _name); ReadFile ($file _dir. $file _name); }

In particular, the last one on the "optional" and "not selectable" forms, do not understand
$surplus = ";  Extract ($_request);  $n =0;     if (empty ($offset))             {$offset =0;}    mysql_query ("Set names ' GB2312 '");  $where = (isset ($surplus) && strlen ($surplus) >0)? "Where surplus= ' $surplus '": '; Don't know  ... $query =mysql_query ("SELECT count (*) as SM from Keti $where");  $row =mysql_fetch_array ($query);  $count = $row [' SM ']; The total number of records      $query =mysql_query ("select * from Keti $where the ORDER by ID ASC limit $offset, $list _num") or Die ("fail");


Reply to discussion (solution)

Extract importing an array into the variable table (the association key is the variable name)

mysql_query ("Set names ' GB2312 '"); Used to notify MySQL of future interactions with the GB2312 character set
It's usually done once after connecting to the database.

By
if ($number 1< ($row [' SN ']-$row [' ssn ']) {
Echo

the number of people can not be less than the number of selected topics, the number of changes failed! ";
SN is an alternative number, SSN selected

No filter criteria Query
Select COUNT (*) as SM from Keti
Query with filter conditions
Select COUNT (*) as SM from Keti where surplus= ' $surplus '

Extract importing an array into the variable table (the association key is the variable name)

mysql_query ("Set names ' GB2312 '"); Used to notify MySQL of future interactions with the GB2312 character set
It's usually done once after connecting to the database.

By
if ($number 1< ($row [' SN ']-$row [' ssn ']) {
Echo

the number of people can not be less than the number of selected topics, the number of changes failed! ";
SN is an alternative number, SSN selected

No filter criteria Query
Select COUNT (*) as SM from Keti
Query with filter conditions
Select COUNT (*) as SM from Keti where surplus= ' $surplus '

This is the last sentence to understand

$where = (isset ($surplus) && strlen ($surplus) >0)? "Where surplus= ' $surplus '": ';
Ternary operations, equivalent to
if (Isset ($surplus) && strlen ($surplus) >0)) {
$where = "where surplus= ' $surplus '";
}else {
$where = ";
}

  • Related Article

    Contact Us

    The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

    If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

    A Free Trial That Lets You Build Big!

    Start building with 50+ products and up to 12 months usage for Elastic Compute Service

    • Sales Support

      1 on 1 presale consultation

    • After-Sales Support

      24/7 Technical Support 6 Free Tickets per Quarter Faster Response

    • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.