Standard Connections


When you create a web data connector that gets data from multiple tables, you can pre-specify how you want to join the tables in Tableau Desktop. Tableau Desktop supports left and inner joins for web data connectors.

Before you create a standard connection, ensure that you have a working web data connector for your tables. For more information on getting data from multiple tables, see the Multiple Tables Tutorial.

Once you have a working connector for multiple tables, complete the following steps to create and use standard connections:

Important: Standard connections are only supported in WDC versions 2.1 and later.

Create the connection objects

For every set of tables in a web data connector that you want to join, you need to create a connection object. A connection object is a JavaScript object that specifies the tables that you want to join, the columns that you want to use to join the tables, and the type of join.

For example, you could use the following connection object to join the tables from the sample created in the Multiple Tables Tutorial.

var standardConnection = {
    "alias": "Joined earthquake data",
    "tables": [{
        "id": "magPlace",
        "alias": "Magnitude and Place"
    }, {
        "id": "timeUrl",
        "alias": "Time and URL"
    }],
    "joins": [{
        "left": {
            "tableAlias": "Magnitude and Place",
            "columnId": "id"
        },
        "right": {
            "tableAlias": "Time and URL",
            "columnId": "id"
        },
        "joinType": "inner"
    }]
};

The connection object includes the following properties:

Pass connection objects to the schemaCallback function

The schemaCallback function takes an array of connection objects as a second parameter. (For connectors that do not include standard connections, you do not need to include this second parameter.)

For example, to pass the sample connection object created above to Tableau, enter the following parameters:

schemaCallback([magPlaceTable, timeUrlTable], [connectionObject]);

You can include multiple connection objects in the array.

Use your standard connections in the simulator

To use a standard connection in the simulator, complete the following steps:

  1. Start the simulator.

  2. Enter the URL for your connector in the Connector URL field.

  3. Click the Show Advanced button to display the Standard Connections interface.

  4. Click the Start Interactive Phase button.

  5. Interact with your connector until you are returned to the simulator.

  6. Optionally, click the Joins tab in the Standard Connections interface to view a diagram of your standard connection.

Use your standard connections in Tableau

To use a standard connection in Tableau, complete the following steps:

  1. Open your connector and complete the interactive phase.

  2. Drag your connection from the Standard Connection pane on the left to the Tables pane in the upper right.

    Drag your connection to the Tables pane.

    The joined tables appear in the Tables pane.

    The joined tables appear.