0 
 <?php
date_default_timezone_set("America/New_York");
require("db_vars.php");

  // Connect to the database
  $dbc = mysqli_connect($db_hostname, $db_database, $db_username, $db_password);


  // Custom function to draw a bar graph given a data set, maximum value, and image filename
  function draw_bar_graph($width, $height, $data, $max_value, $filename) {
    // Create the empty graph image
    $img = imagecreatetruecolor($width, $height);

    // Set a white background with black text and gray graphics

    $bg_color = imagecolorallocate($img, 255, 255, 255);       // white

    $text_color = imagecolorallocate($img, 255, 255, 255);     // white

    $bar_color = imagecolorallocate($img, 0, 0, 0);            // black
    $border_color = imagecolorallocate($img, 192, 192, 192);   // light gray

    // Fill the background
    imagefilledrectangle($img, 0, 0, $width, $height, $bg_color);

    // Draw the bars
    $bar_width = $width / ((count($data) * 2) + 1);
    for ($i = 0; $i < count($data); $i++) {
      imagefilledrectangle($img, ($i * $bar_width * 2) + $bar_width, $height,
        ($i * $bar_width * 2) + ($bar_width * 2), $height - (($height / $max_value) * $data[$i][1]), $bar_color);
      imagestringup($img, 5, ($i * $bar_width * 2) + ($bar_width), $height - 5, $data[$i][0], $text_color);
    }

    // Draw a rectangle around the whole thing
    imagerectangle($img, 0, 0, $width - 1, $height - 1, $border_color);

    // Draw the range up the left side of the graph
    for ($i = 1; $i <= $max_value; $i++) {
      imagestring($img, 5, 0, $height - ($i * ($height / $max_value)), $i, $bar_color);
    }

    // Write the graph image to a file
    imagepng($img, $filename, 5);

    imagedestroy($img);
  } // End of draw_bar_graph() function

 // if (mysqli_num_rows($data) != 0) {
    // First grab the user's responses from the response table (JOIN to get the topic and category names)
   $query = "SELECT ts.species_name, COUNT(ti.species_id)  " .
      "FROM tree_species ts " .
      "INNER JOIN tree_individuals ti ON ts.species_id = ti.species_id " .
      "GROUP BY ts.species_name'";
    $data = mysqli_query($dbc, $query);
    $tree_totals = array();
    while ($row = mysqli_fetch_array($data)) {
      array_push($tree_totals, $row);
    }

        // Generate and display the mismatched category bar graph image
        echo '<h4>Mismatched category breakdown:</h4>';
        draw_bar_graph(480, 240, $tree_totals, 5, 'treetotalgraph.png');
        echo '<img src="treetotalgraph.png" alt="Tree total graph" /><br />';
//}

mysqli_close($dbc);
?>

产生以下错误

警告：mysqli_query() 期望参数 1 为 mysqli，布尔值在第 54 行的 G:\Students\test.php 中给出

警告：mysqli_fetch_array() 期望参数 1 为 mysqli_result，在第 56 行的 G:\Students\test.php 中给出 null

不匹配的类别细分：

警告：imagepng() [function.imagepng]：无法打开“treetotalgraph.png”进行写入：第 43 行 G:\Students\test.php 中的权限被拒绝

警告：mysqli_close() 期望参数 1 为 mysqli，布尔值在第 68 行的 G:\Students\test.php 中给出

4

1 回答 1

2

正是它所说的：您没有明确设置时区，php.ini 文件中也没有设置。

将此添加到代码的开头：

date_default_timezone_set("America/New_York");
于 2012-12-10T05:11:27.110 回答