检查mysql中是否存在值 [英] Check if value exist in mysql

问题描述

我有一个小的脚本，用于从csv文件将数据上传到mysql数据库，并且我想检查csv文件内部的值列表.

I have a small script to upload data to mysql database from a csv file and I want to check the list of values that are inside of the csv file.

CSV文件:

code,alert_quantity
12345,10

PHP文件:

    <?php
    $link_id = mysql_connect("localhost", "root", "")
               or die("Could not connect.");

    if(!mysql_select_db("database",$link_id))
    die("database was not selected.");

    function _checkIfCodeExists($code){

    $sql        = "SELECT COUNT(*) AS count_no FROM products WHERE code = ?";
    $count      = $sql;
    if($count > 0){
        return true;
    }else{
        return false;
    }
    }

    function _updateData($line_of_data){
    $code            = $line_of_data[0];
    $newAlert       = $line_of_data[1];

    $sql = "UPDATE ";
}

    $file_handle = fopen("file.csv", "r");

    while (($line_of_data = fgetcsv($file_handle, 1000, ",")) !== FALSE) {

    $query = mysql_query("SELECT * FROM products WHERE code ='$line_of_data[0]'") or die(mysql_error());
    $message = '';
    $count   = 1;

    if(_checkIfCodeExists($line_of_data[0])){
        try{
            _updateData($_data);
            $message .= $count . '> Success:: Product with code  (' . $line_of_data[1] . ') Exist (' . $line_of_data[0] . '). <br />';

        }catch(Exception $e){
            $message .=  $count .'> Error:: While updating alert (' . $line_of_data[1] . ') of code (' . $line_of_data[0] . ') => '.$e->getMessage().'<br />';
        }
    }else{
        $message .=  $count .'> Error:: Product code   (' . $line_of_data[0] . ')   Doesnt exist<br />';
    }
    $count++;
}
echo $message;

?>

我不想导入此值，只是想检查是否存在并获取结果.

I don't want to import this values, just I want to check if exist and get the result.

感谢您的帮助.

推荐答案

正如其他人所说，您应该真正使用PDO.但是，要回答您的问题，mysql_num_rows是您的解决方案.

As others have said, you should really use PDO. But, to answer your question, mysql_num_rows is your solution.

$query = mysql_query("SELECT * FROM products WHERE code='$line_of_data[0]' AND alert_quantity = '$line_of_data[1]'") or die(mysql_error());

if (mysql_num_rows($query))
// Data is already in database
else
// Data not in database

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