DataBind Charts to HarperDB Data

DataBinding facilitates two-way interaction with data through UI controls. Using the CData ADO.NET Provider for HarperDB streamlines the process of binding HarperDB data to Windows Forms and Web controls within Visual Studio. In this article, we will demonstrate using wizards to establish a binding between HarperDB data and a chart that dynamically updates. Additionally, the code walk-through section will guide you through the creation of a chart using just 10 lines of code.

Binding Data to a Chart

DataBinding to a Chart consists of three steps: Instantiate the control, configure the data source, and databind.

Configure the Connection and Select Database Objects

To create a chart control and establish a connection to HarperDB, follow the steps outlined below using the Data Source Configuration Wizard. Within the wizard, you'll have the option to choose the specific HarperDB entities you wish to bind to.

1. In a Windows Forms project, drag and drop a Chart control from the toolbox to the form. In the Data section of the Chart properties, select DataSource and then select Add Project Data Source from the menu. 👁 Add a data source to be bound to the chart.
   
2. In the Data Source Configuration Wizard that appears, select Database -> Dataset.
3. In the Choose Your Data Connection step, click New Connection.

4. In the Add Connection dialog, click Change to select the CData HarperDB Data Source.

   Below is a typical connection string:

   Server=127.0.0.1;User=admin;Password=1234;

   Set the Server, User, and Password connection properties to connect to HarperDB. Set UseSSL to secure connections with TLS/SSL.

   When you configure the connection, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.

   👁 Connection properties for the selected data source in the Add Connection dialog. (Salesforce is shown.)
   
5. Choose the database objects you want to work with. This example uses the Customers table. 👁 Select database objects. (Salesforce is shown.)
   

DataBind

After adding the data source and selecting database objects, you can bind the objects to the chart. This example assigns the x-axis to City and the y-axis to CompanyName.

1. In the Chart properties, click the button in the Series property to open the Series Collection Editor.
2. In the Series properties, select the columns you want for the x- and y-axes: Select columns from the menu in the XValueMember and YValueMember properties.

The chart is now databound to the HarperDB data. Run the chart to display the current data. 👁 The chart, filled with data at run time.

Code Walk-through

DataBinding to HarperDB data requires only a few lines of code and can be completed in three easy steps.

1. Connect to HarperDB.
2. Create the HarperDBDataAdapter to execute the query and create a DataSet to be filled with its results.
3. DataBind the result set to the chart.

Below is the complete code:

HarperDBConnection conn = new HarperDBConnection("Server=127.0.0.1;User=admin;Password=1234;");
HarperDBCommand comm = new HarperDBCommand("SELECT City, CompanyName FROM Customers WHERE Country = 'US'", conn);
HarperDBDataAdapter da = new HarperDBDataAdapter(comm);
DataSet dataset = new DataSet();
da.Fill(dataset);

chart1.DataSource = dataset; 
chart1.Series[0].XValueMember = "City";
chart1.Series[0].YValueMembers = "CompanyName";
// Insert code for additional chart formatting here.
chart1.DataBind();