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检查我的数据库表中是否存在值

[英]check if a value exists in my database table

I want to check if a URL exists in my MySQL database table for example if Url=exist , message=url already exist 我要检查,如果一个URL在例如我的MySQL数据库表存在,如果Url=existmessage=url已经存在

<?php
if(isset($_POST['Submit'])){
    $dbhost = 'localhost';
    $dbuser = '####';
    $dbpass = '#######';
    $conn = mysql_connect($dbhost, $dbuser, $dbpass);
    $Title = $_POST['Title'];
    $Url = $_POST['Url'];
    $email_data = $_POST['email_data'];
    $type_data = $_POST['type_data'];
    $sql = "INSERT INTO table ". "(Title,Url,email_data,type_data)"."VALUES('$Title','$Url','$email_data','$type_data')";
    mysql_select_db('dbname');
    $retval = mysql_query( $sql, $conn );
        if(! $retval ){
            die('Could not enter data: ' . mysql_error());
        }
    echo "<script type='text/javascript'>alert('submitted successfully!')</script>";
    mysql_close($conn);
} else {
?>

You can do like this 你可以这样

$sql = "SELECT Url FROM 'your_table_name' WHERE Url = $_POST['Url']";

Run this sql and if it is return true you can say its exist. 运行此sql ,如果它返回true ,则可以说它存在。

Its a bit hard know what you are doing by just looking at the code but if you wondering how to check if something is in the database you could do like this: 仅查看代码就很难知道您在做什么,但是如果您想知道如何检查数据库中是否存在某些内容,可以执行以下操作:

PHP: PHP:

$sql = mysql_query("SELECT * FROM dbname WHERE Url='$Url'");
if(mysql_num_rows($sql) > 0){
    echo "alreday exist";
}
$query = mysql_query('select url from table-name where url=$_post['url']');
if(mysql_fetch_rows($query) != 0){
echo "URL allready Exists";
}else{ 
Insert Query 
}

Hi, Try this code. 嗨,试试这个代码。

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