为什么正则表达式在我的php程序中不起作用

Question

i am trying to insert a value in a table but first the data i enter i check the pattern of the data entered using regular expressions

this is my code ..but it is working can anyone tell me the problem with my code please ?

<?php
        extract($_POST);
        $host="localhost"; // Host name
        $username="root"; // Mysql username
        $password="rootpass"; // Mysql password
        $db_name="myshop"; // Database name

        $name=trim($Gname); //trimming the name

        $pattern="/^[a-zA-Z]$/";
        mysql_connect("$host", "$username", "$password")or die("cannot connect server ");
        mysql_select_db("$db_name")or die("cannot select DB");


        if ($name=="")
            echo ("Missing Info");
        else
        {
            if (isset($name))
            {
            if (preg_match($pattern,$name))
                $sql="INSERT INTO ayesha VALUES('$name')";
            else
                echo("wrong syntax");
            }
            else
            {
            echo("missing info");
            }
        ?>

Answer 1

try this $pattern="/[a-zA-Z]+/"; instead $pattern="/^[a-zA-Z]$/";

$pattern="/[a-zA-Z]+/";
//your code
if (!empty($name)) {
    if (preg_match($pattern,$name)) {
        $sql="INSERT INTO ayesha VALUES('$name')";
    } else {
        echo("wrong syntax");
    }
} else {
    echo("missing info");
}
    ?>