php - PHP：过滤特定列的mysql_query结果？

Question

有没有一种快速的方法来过滤 mysql_query 结果以获取仅包含特定列的值的列表？

$query = mysql_query("SELECT * FROM users");
$list_of_user_names = get_values($query,"names");

要用来代替的函数的名称是get_values什么？

Answer 1

Assuming your field name in databse is "names"

$query = mysql_query("SELECT names FROM users");

while($row = mysql_fetch_assoc($query)){
    echo $row['names'];
    echo "<br>";
}

NOTE : mysql_* functions are deprecated in new version of php, use mysqli_* or PDO

Answer 2

尝试这个：

$query = mysql_query("SELECT names FROM users");

if (!$query) {
    echo "Could not successfully run query from DB: " . mysql_error();
    exit;
}

if (mysql_num_rows($query) == 0) {
    echo "No rows found, nothing to print so am exiting";
    exit;
}

// While a row of data exists, put that row in $row as an associative array
// Note: If you're expecting just one row, no need to use a loop
// Note: If you put extract($row); inside the following loop, you'll
//       then create $names

while ($row = mysql_fetch_assoc($query)) {
    echo $row["names"];

}

Answer 3

使用以下功能。

  function get_values($q,$c)
  {
       $arr = array();
       while($row = mysql_fetch_array($q))
       {
            $arr[] = $row[$c];
       }
       return $arr; // return all names value.
  }