php - PHP变量不显示值

Question

我将 MySQL Query 值存储在 PHP 变量中，但它不显示数据。PS：数据在MySQL表列中可用。

 <?php 
$cmsca= mysql_query("SELECT SUM(qa_effort) FROM tbl_uat WHERE product='CAP'");
     while ($cresulta = mysql_fetch_array ($cmsca)) 
         $arra[0] = $cresulta[0];
         echo $arra[0];
?>

我没有线索，上面的代码有什么问题？需要帮忙！

问候

Answer 1

尝试这个

   <?php 
  $cmsca= mysql_query("SELECT SUM(qa_effort) as sums FROM tbl_uat WHERE product='CAP'");
   while ($cresulta = mysql_fetch_array($cmsca)) 
   {
     echo $cresulta['sums'];
   }
  ?>

Answer 2

首先，不要使用 mysql_query， - 它已被弃用，请改用http://www.php.net/manual/en/mysqli.query.php。接下来，您需要在运行查询之前连接到数据库；

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

$result = mysqli->query("SELECT SUM(qa_effort) as sums FROM tbl_uat WHERE product='CAP'");
while ($row = $result->fetch_array()) {
    var_dump($row);
}

$mysqli->close();
?>

Answer 3

试试这个怎么样：

<?php
 $arra = array(); 
 $cmsca= mysql_query("SELECT SUM(qa_effort) FROM tbl_uat WHERE product='CAP'");
 while ($row = mysql_fetch_array ($cmsca)) 
     $arra = $row;
     print_r($arra);
 ?>