php - JpGraph来自mysql数据的折线图

Question

我希望能够进行查询，从数据库中获取数字，并使用 JpGraph 将这些数字呈现在折线图上。

任何人都可以帮助我，或指导我解决这个问题吗？

谢谢大家!

Answer 1

这是我的代码。 db.php用于定义数据库连接 `

require_once("db.php");  //include database connection
require_once("constant.php");    //include database connection
require_once ('jpgraph/src/jpgraph.php');
require_once ('jpgraph/src/jpgraph_line.php');
$default=true;
$filter="";

if(isset($_GET["timelapse"]))   $timelapse=$_GET["timelapse"];
else $timelapse=TODAY;

$strQueryString="SELECT Date_Time, DissolvedOxygen   as DissolvedOxygen FROM datareading";


//echo $strQueryString;
$strQueryString.= " ORDER BY Date_Time ASC";
$query = mysql_query($strQueryString);
$xdata=array();
$ydata=array();
while($row=mysql_fetch_array($query)){
    $date = date_create($row["Date_Time"]);
    $xdata[]=date_format($date," h:i a");
    $ydata[]=$row["DissolvedOxygen"];

}
//print_r($xdata);
$graph = new Graph(920,500); // Initialize Graph
$graph->SetScale("intlin");
$graph->SetMargin(80,30,40,50);
$graph->SetMarginColor('white');
$graph->SetFrame(false,'blue',3);
//Set Title Attributes
$graph->title->Set("Dissolved Oxygen Level");
$graph->yaxis->SetTitleMargin(50);
$graph->title->SetFont(FF_ARIAL,FS_BOLD,12);

//Set Subtitle Attributes
$graph->subtitle->Set("Last 24 Hours");
$graph->subtitle->SetFont(FF_ARIAL,FS_BOLD,10);
$graph->subtitle->SetColor('black');
//$graph->xaxis->SetLabelAngle(90);
$graph->xaxis->SetTickLabels($xdata);
$graph->xaxis->SetTextLabelInterval(2);

// Use Arial font
$graph->xaxis->SetFont(FF_ARIAL,FS_BOLD,9);
$graph->SetAxisLabelBackground(LABELBKG_XAXIS,'orange','red','lightblue','red');
$graph->yaxis->SetFont(FF_ARIAL,FS_BOLD,9);
$graph->xgrid->Show();

// Create the plot line
$p1 = new LinePlot($ydata);
$p1->value->SetFont( FF_FONT1, FS_BOLD); 
$p1->value->SetAlign('center');

//Set y-axis title
$graph->yaxis->title->Set("Dissolved Oxygen (mg/L or ppm)");
$graph->yaxis->SetLabelAlign('right','bottom');

$graph->Add($p1);
//print_r($xdata);
$graph->Stroke();`