用PHP和MYSQL建立计数器过程详解

　2005-01-14 16:38:45　来源：WEB开发网　闂傚倷绶氬ḿ褍螞閹绢喖绠柨鐕傛嫹

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核心提示：运行MySQL.EXEmysql> create database counter;Query OK, 1 row affected (0.10 sec)mysql> use counter;Database changedmysql> create table tl(id integer(2),co

运行MySQL.EXE
mysql> create database counter;
Query OK, 1 row affected (0.10 sec)

mysql> use counter;
Database changed

mysql> create table tl(id integer(2),count integer(5));
Query OK, 0 rows affected (0.21 sec)

mysql> show columns from tl;
+-------+--------+------+-----+---------+-------+
| Field | Type　 | Null | Key | Default | Extra |
+-------+--------+------+-----+---------+-------+
| id　 | int(2) | YES |　　 | NULL　 |　　　 |
| count | int(5) | YES |　　 | NULL　 |　　　 |
+-------+--------+------+-----+---------+-------+
2 rows in set (0.05 sec)

mysql> select * from tl;
Empty set (0.08 sec)

mysql> insert into tl(id,count) values(1,1);
Query OK, 1 row affected (0.02 sec)

mysql> select * from tl;
+------+-------+
| id　 | count |
+------+-------+
|　 1 |　　 1 |
+------+-------+
1 row in set (0.03 sec)

下面编写HTML文件内容：

<?php
$myvar = "来访人数：";
echo $myvar;
?>

<?php
mysql_connect() or die("there are PRoblems to connect to mysql!");
$query="select * from tl";
$result=mysql_db_query("counter",$query);
if($result){
$r=mysql_fetch_array($result);
$counter=$r["count"];
$counter=$counter+1;
echo $counter;
$query="update tl set count='$counter' where id=1";
$result=mysql_db_query("counter",$query);
mysql_close();
}
?>
</body>
</html>