Use PHP+MySQL to build chat room function example code_PHP tutorial

Below, take a simple chat room design as an example to introduce the application of PHP+MySQL in web development

1. Overall design

　1.1 Conception and planning:
The basic principle of the chat room is to store the speech data sent by each user connected to the same web page, and then transmit all the speech data to each user. In other words, the function of a chat room is realized by using a database to collect everyone's speeches and transmitting the data in the database to everyone.
　1.2 Table Design
First use MySQL to create a chat table to store user comments:

Copy code The code is as follows:

mysql> CREATE TABLE chat
-> (chtime DATATIME,
-> nick CHAR(10) NOT NULL,
->words CHAR(150));

Only three fields are set in the table, chtime is the time of speech, nick is the nickname of the speaker, words is the content of the speech, the speech can be up to 150 characters
1.3 Web design
One of the most A simple chat room usually requires two page frames: one page frame is a form for users to enter comments, and the other is used to display everyone's comments. Therefore, the code segment usually requires at least the following segments:
Create the structure of the page frame (main.php)
The program segment that displays everyone’s speech (cdisplay.php)
The program segment that transmits the user’s speech (speak.php )
User login to enter the chat room program segment (login.php)

2. Code design

After the above planning is completed, you can start the code design. Using php can realize the above functions very simply.
　2.1 User login login.php, this code is a complete HTML web page

Copy code The code is as follows:

Please enter your nickname

　

After the user submits his nickname, he enters For chat rooms, the following processing is handled by main.php.
　2.2 Page frame main code segment main.php:

Copy code The code is as follows:

setcookie("nick",$nick) //Use cookies to record user nicknames, which is a commonly used method of passing variables
?>

　2.3 Display speech cdisplay.php
This code The task of the segment is to take out the data from the table chat and display it in the page frame. Each time it is refreshed, the 15 most recent statements in the database are fetched. At the same time, in order to prevent the database from growing indefinitely, it is necessary to design the function of deleting old data. The code is as follows

Copy code The code is as follows:

　$link_ID=mysql_connect(“main”,”root”);
　/ /Link Mysql server server name is main, administrator name is root
mysql_select_db("abc"); //Select database
$str="select * from chat ORDER BY chtime;"; //Query string
$result=mysql_query($str, $link_ID); //Send query
$rows=mysql_num_rows($result); //Get the number of records of query results
//Get the last 15 statements , and display
　@mysql_data_seek($resut,$rows-15); //Move the record pointer to the first 15 records
　if ($rows<15) $l=$rows; else $l=15; //The total number of records is less than 15, then the maximum number of records is
for ($i=1;$i<=$l;$i++) {
list($chtime,$nick,$words)=mysql_fetch_row ($result);
echo $chtime; echo ““;echo $nick; echo”:” ; echo $words; echo “
”;
}
//Clear out-of-date libraries Data
　@mysql_data_seek($result,$rows-20); //Move the record pointer to the first 20 records
　list($limtime)=mysql_fetch_row($result);
　$str="DELETE FROM chat WHERE chtime<'$limtime' ;" ;
　$result=mysql_query($str,$link_ID); //Send the query string, leaving only the first 20 records in the library
mysql_close($link_ID) ;
?>

　2.4 Send speech to database speak.php

Copy code The code is as follows:

< ;/head>

　If ($words)
　{ $link_ID=mysql_connect(“main”,”root”); ”); //The database name is abc
　$time=date(y).date(m).date(d).date(h).date(i).(date(s); //Get the current Time
　$str="INSERT INTO chat(chtime,nick,words) values ​​
　　('$time','$nick','$words');";
　mysql_query($str,$ link_ID); //Send the speech to the database
　mysql_close($link_ID);
　}
?>
//Enter the speech form

　
　

After completing the above work, a simple chat room is completed . Of course, designers can make some personalized designs based on personal preferences, such as adding a page frame to display the list of current chat room members, adding speaking emoticons, obtaining the speaker's IP, further beautifying the page, etc.

http://www.bkjia.com/PHPjc/325728.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/325728.htmlTechArticleThe following takes a simple chat room design as an example to introduce the application of PHP+MySQL in web development 1. Overall design 1.1 Conception and planning: The basic principle of the chat room is to connect everyone with the same...