如何在MySQL中将$ variable设置为DATE_FORMAT

Question

I have created one variable for changing date format in MySQL query but it is not working for me so is there any way to use a variable as a date-format in MySQl query ?

My code is here

<?php
    $con = mysql_connect();
    mysql_select_db();
    $dateFormat = '%d-%m-%Y';
    $result = mysql_query("SELECT *, DATE_FORMAT(2014-11-18, $dtFormat) AS niceDate FROM TableName;");
    $data = array();
    while ( $row = mysql_fetch_row($result, true) )
    {
        $data[] = $row;    
    }
    echo json_encode($data);
?>

Answer 1

You need to pass $dateFormat instead of $dtFormat as a string in MySQL.

<?php
$con = mysql_connect();
mysql_select_db();
$dateFormat = '%d-%m-%Y';
$result = mysql_query("SELECT *, DATE_FORMAT('2014-11-18', '".$dateFormat."') AS niceDate FROM TableName;");
$data = array();
while ( $row = mysql_fetch_row($result, true) )
{
    $data[] = $row;
}
echo json_encode($data);
?>