Question

通过获取mysql数据库表值，想要创建一个PHP条形图。我用JpGraph绘制条形图。我想从'学生'表中获取数据。我有一个名为“category”的列，其中值为“Full time”或“Part time”。我想算不上。类别为“全时”的行和其中类别为“兼职”的行数。 x轴应为类别，y轴应为相关行数。 PHP代码如下;

<?php
 require_once('/jpgraph-3.5.0b1/src/jpgraph.php');
 require_once('/jpgraph-3.5.0b1/src/jpgraph_bar.php'); 
 $db = mysql_connect("localhost", "root","") or die(mysql_error());

 mysql_select_db("mphildatabase",$db) or die(mysql_error());

 $sql1 = mysql_query("SELECT category FROM student") or die(mysql_error());
 $sql2 = mysql_query("SELECT COUNT(*) FROM student WHERE category='Full Time'") or die(mysql_error());
 $sql3 = mysql_query("SELECT COUNT(*) FROM student WHERE category='Part Time'") or die(mysql_error());
 while($row1 = mysql_fetch_array($sql1))
 {
 $row2 = mysql_num_rows($sql2);
 $row3 = mysql_num_rows($sql3);
 $data[] = $row2;
 //$data[] = $row3;
 $leg[] = $row1['category'];
 }
 $graph = new Graph(950,750,"auto");
 $graph->SetScale("textint");
 $graph->img->SetMargin(50,30,50,50);

 $graph->SetShadow();

  $graph->xaxis->SetTickLabels($leg);

  $bplot = new BarPlot($data);
  $bplot->SetFillColor("lightgreen"); 
  $bplot->value->Show();
  $bplot->value->SetFont(FF_ARIAL,FS_BOLD);
  $bplot->value->SetAngle(45);
  $bplot->value->SetColor("black","navy");

  $graph->Add($bplot);
  $graph->Stroke(); ?>

这将给出每行的单独条形图。每行都会打印条形图，所有这些条形图的y轴值将为1.如何绘制仅有2个条形图的条形图，其中一个显示类别为“全时”的行数和其他条形图显示类别为“兼职”的行数谢谢！

Answer 1

您必须只使用一个查询，并在一个循环中填充数组。您的查询必须是：

"SELECT count(*) as num_rows, category from 
student WHERE category ='Full Time' or Category= 'Part Time'
Group by Category
  "

...

while($row1 = mysql_fetch_array($sql1))
{
$leg[] = $row1['category'];
$data[] = $row1['num_rows']
}

JpGraph：使用MySQL数据创建PHP条形图

1 个答案: