英文:
JFreechart chart with Time from SQL Database
问题
public class JDBCTest {
private void display() {
JFrame f = new JFrame("JDBCTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JDBCXYDataset jds = createDataset();
JFreeChart chart = ChartFactory.createTimeSeriesChart(
"Inventory", "Date", "Count", jds, true, true, false);
f.add(new ChartPanel(chart));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private JDBCXYDataset createDataset() {
try {
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:", "", "");
Statement st = conn.createStatement();
st.execute("DROP TABLE IF EXISTS Test ");
st.execute("create table Test(Date_Heure timestamp, PV float)");
String Date_Debut = "2020-06-25 13:28:08";
String Date_Fin = "2020-06-26 13:28:08";
String sql1 = "INSERT INTO Test (Date_Heure,PV) "
+ "SELECT TABLE ,TABLE "
+ "FROM TABLE "
+ "WHERE Date_Heure BETWEEN ? AND ?";
PreparedStatement ps = conn.prepareStatement(sql1);
ps.setString(1, Date_Debut);
ps.setString(2, Date_Fin);
ps.executeUpdate();
JDBCXYDataset jds = new JDBCXYDataset(conn);
jds.executeQuery("select TABLE , TABLE from Test");
return jds;
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
return null;
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new JDBCTest().display();
}
});
}
}
Additional information:
Date_Timetype istimestampPVtype isfloat
英文:
I'm new with JFreeChart and I'm trying to create a chart that display a value on the y-axis and the time on the x-axis.
All theses data (value and time) are already in my database and I have something like a value for each 3 to 4 seconds.
However I do not want to display everything or to be dynamic. I just want to display a chart that shows all the values from 2020-06-16 10:31:52 to 2020-06-29 11:31:52 for example (but everything is already in my Database as I said).
Here is my variation of this (without all the imports) :
public class JDBCTest {
private void display() {
JFrame f = new JFrame("JDBCTest");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JDBCXYDataset jds = createDataset();
JFreeChart chart = ChartFactory.createTimeSeriesChart(
"Inventory", "Date", "Count", jds, true, true, false);
f.add(new ChartPanel(chart));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private JDBCXYDataset createDataset() {
try {
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:","", "");
Statement st = conn.createStatement();
st.execute("DROP TABLE IF EXISTS Test ");
st.execute("create table Test(Date_Heure timestamp, PV float)");
String Date_Debut = "2020-06-25 13:28:08";
String Date_Fin = "2020-06-26 13:28:08";
String sql1 = "INSERT INTO Test (Date_Heure,PV) "
+ "SELECT TABLE ,TABLE "
+ "FROM TABLE "
+ "WHERE Date_Heure BETWEEN ? AND ?";
PreparedStatement ps = conn.prepareStatement(sql1);
ps.setString(1,Date_Debut);
ps.setString(2,Date_Fin);
ps.executeUpdate();
JDBCXYDataset jds = new JDBCXYDataset(conn);
jds.executeQuery("select TABLE , TABLE from Test");
return jds;
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
return null;
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new JDBCTest().display();
}
});
}
}
EDIT : The error was comming from the Database and not from the code itself.
Edit :
The code is inspired around trashgod's work http://stackoverflow.com/a/24762078/230513
additional information :
Date_Time type's timestamp
PV type's float
答案1
得分: 2
使用 JDBCXYDataset 的示例引用1也适用于 JDBCCategoryDataset,如下所示并且在您的原始问题中有展示。使用 JDBCCategoryDataset,"第一列将是类别名称,剩余列将是值(每列代表一系列)";使用 JDBCXYDataset,"第一列将是 x 轴,剩余列为 y 轴的值。" 因此,我预期您的查询可能是这样的:
SELECT Date_Time, PV …
由于您的域轴是时间,请考虑旋转标签位置,如此处所示。在决定时,请注意 TimeSeries 在方向性方面较不灵活,但在格式化方面更具灵活性。

我的数据库中的值是
Float类型。
对示例进行的以下更改演示了使用浮点数值。请注意,PV 是 float 类型,而且 PreparedStatement 使用了 setFloat()。
JDBCCategoryDataset jds = createDataset();
JFreeChart chart = ChartFactory.createLineChart("Test", "Time", "PV",
jds, PlotOrientation.VERTICAL, true, true, false);
CategoryPlot plot = (CategoryPlot) chart.getPlot();
CategoryAxis domain = plot.getDomainAxis();
plot.getDomainAxis().setCategoryLabelPositions(CategoryLabelPositions.UP_45);
…
private JDBCCategoryDataset createDataset() {
try {
Connection conn = DriverManager.getConnection(
"jdbc:h2:mem:test", "", "");
Statement st = conn.createStatement();
st.execute("create table data(when timestamp, pv float)");
PreparedStatement ps = conn.prepareStatement(
"insert into data values (?, ?)");
Calendar c = Calendar.getInstance();
for (int i = 0; i < N; i++) {
ps.setTimestamp(1, new Timestamp(c.getTimeInMillis()));
ps.setFloat(2, (float)r.nextGaussian() + 2);
ps.execute();
c.add(Calendar.SECOND, r.nextInt(60 * 60));
}
JDBCCategoryDataset jds = new JDBCCategoryDataset(conn);
jds.executeQuery("select when, pv from data");
return jds;
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
return null;
}
英文:
The example cited using JDBCXYDataset also works with JDBCCategoryDataset, as shown below and in your original question. Using JDBCCategoryDataset, "The first column will be the category name and [the] remaining columns [will be] values (each column represents a series);" using JDBCXYDataset, "The first column will be the x-axis and remaining columns y-axis values. " As a result, I would expect your query to be something like this:
SELECT Date_Time, PV …
As your domain axis is time, consider rotating the label positions, as shown here. When deciding, note that a TimeSeries is less flexible about orientation but more flexible about formatting.
>the values in my database are Float.
The following changes to the example illustrate using floating point values. Note that PV is of type float, and the PreparedStatement uses setFloat().
JDBCCategoryDataset jds = createDataset();
JFreeChart chart = ChartFactory.createLineChart("Test", "Time", "PV",
jds,PlotOrientation.VERTICAL, true, true, false);
CategoryPlot plot = (CategoryPlot) chart.getPlot();
CategoryAxis domain = plot.getDomainAxis();
plot.getDomainAxis().setCategoryLabelPositions(CategoryLabelPositions.UP_45);
…
private JDBCCategoryDataset createDataset() {
try {
Connection conn = DriverManager.getConnection(
"jdbc:h2:mem:test", "", "");
Statement st = conn.createStatement();
st.execute("create table data(when timestamp, pv float)");
PreparedStatement ps = conn.prepareStatement(
"insert into data values (?, ?)");
Calendar c = Calendar.getInstance();
for (int i = 0; i < N; i++) {
ps.setTimestamp(1, new Timestamp(c.getTimeInMillis()));
ps.setFloat(2, (float)r.nextGaussian() + 2);
ps.execute();
c.add(Calendar.SECOND, r.nextInt(60 * 60));
}
JDBCCategoryDataset jds = new JDBCCategoryDataset(conn);
jds.executeQuery("select when, pv from data");
return jds;
} catch (SQLException ex) {
ex.printStackTrace(System.err);
}
return null;
}
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