Datalist extract template rows

Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Visit chat. Linked 2. Related 1. You can also place a Table control in a template and display the rows of the table.

Use the ExtractTemplateRows property to specify whether the rows of a Table control defined in each template of a DataList control are extracted and displayed. All rows extracted from the templates of the DataList control are displayed in a single table. This allows you to create a single table from other smaller tables and still maintain the features of the DataList control.

When this property is set to true , you must provide a well-formed Table control for each template you want to include in the DataList control. Click the Hide All Unused Fields button to remove these hidden fields from the extract. In the subsequent dialog box, select a location to save the extract, give the extract file a name, and then click Save. If the Save dialog box does not display, see the Troubleshoot extracts section, below. After you create an extract, the workbook begins to use the extract version of your data.

However, the connection to the extract version of your data is not preserved until you save the workbook. This means if you close the workbook without saving the workbook first, the workbook will connect to the original data source the next time you open it. When you're working with a large extract, you might want to create an extract with a sample of the data so you can set up the view while avoiding long queries every time you place a field on a shelf on the sheet tab.

You can then toggle between using the extract with sample data and using the entire data source by selecting a data source on the Data menu and then selecting Use Extract. Because extracts are saved to your file system, it is possible to connect directly to them with a new Tableau Desktop instance.

This is not recommended for a few reasons:. When you remove an extract, you can choose to Remove the extract from the workbook only or Remove and delete the extract file.

The latter option will delete the extract from your hard drive. If you open a workbook that is saved with an extract and Tableau cannot locate the extract, select one of the following options in the Extract Not Found dialog box when prompted:. Locate the extract: Select this option if the extract exists but not in the location where Tableau originally saved it.

Click OK to open an Open File dialog box where you can specify the new location for the extract file. Remove the extract: Select this option if you have no further need for the extract. This is equivalent to closing the data source.

All open worksheets that reference the data source are deleted. Deactivate the extract: Use the original data source from which the extract was created, instead of the extract.

Regenerate the extract: Recreates the extract. All filters and other customizations you specified when you originally created the extract are automatically applied. Tableau generally recommends that you use the default data storage option, Logical Tables, when setting up and working with extracts. In many cases, some of the features you need for your extract, like extract filters, are only available to you if you use the Logical Tables option. The Physical Tables option should be used sparingly to help with specific situations such as when your data source meets the Conditions for using the Physical Tables option and the size of your extract is larger than expected.

To determine if the extract is larger than it should be, the sum of rows in the extract using the Logical Tables option must be higher than the sum of rows of all the combined tables before the extract has been created. If you encounter this scenario, try using the Physical Tables option instead. When using the Physical Tables option, other options to help reduce the data in your extract, like extract filters, aggregation, Top N and Sampling are disabled.

If you need to reduce the data in an extract that uses the Physical Tables option, consider filtering the data before it is brought into Tableau Desktop using one of the following suggestions:.

Connect to your data and define filters using custom SQL: Instead of connecting to a database table, connect to your data using custom SQL instead. When creating your custom SQL query, make sure that it contains the appropriate level of filtering that you need to reduce the data in your extract. Define a view in the database: If you have write access to your database, consider defining a database view that contains just the data you need for your extract and then connect to the database view from Tableau Desktop.

If you want to secure extract data at the row level, using the Physical Tables option is the recommended way to achieve this scenario. Troubleshoot extracts Creating an extract takes a long time: Depending on the size of your data set, creating an extract can take a long time. However, after you have extracted the data and saved it to your computer, performance can improve.

Extract is not created: If your data set contains a really large number of columns e. If you encounter problems, consider extracting fewer columns or restructuring the underlying data. Save dialog does not display or extract is not created from a. When an extract is created from a packaged workbook. To access the extract file that you created from the packaged workbook, you must unpackage the workbook. For more information, see Packaged Workbooks. Tableau Desktop and Web Authoring Help.

Version: Extracts are advantageous for several reasons: Supports large data sets: You can create extracts that contain billions of rows of data. Latest changes to extracts Extracts in the web Beginning with version Logical and physical table extracts With the introduction of logical tables and physical tables in the Tableau data model in version Changes to values and marks in the view To improve extract efficiency and scalability, values in extracts can be computed differently in versions Format of date and date time values In versions More specifically, the rules can be generalized as the following: Dates are evaluated and then parsed by column, not by row.

Dates are evaluated and then parsed based on the locale of where the workbook was created, not on locale of the computer where the workbook is opened. Where the date is ambiguous and can be interpreted in several different ways, the date will be interpreted based on the format Tableau has determined for that column. For some examples, see Date scenario 1 and Date scenario 2 below.

For an example, see Date scenario 3. When a function doesn't have enough information to derive the time, it can interpret a value as " When a function doesn't have enough information to derive the day, it can interpret a value as "1" or "January" for month. When a function parses years, it is interpreted as the following: Year "07" is interpreted as "" Year "17" is interpreted as " After Tableau determines the date format, all other dates in the column that deviate from the format become null values.

When a function has to parse date values that contain trailing characters. If you forget to clear the data bindings and a row template is re-bound, you will see an exception that states that binding to the given property would create a duplicate binding which is not allowed.

Check to be sure that you have cleared the DataBindings collection on all controls in the template in the Bind method. This problem can be avoided by using the template control's overloaded AddBinding method. General binding errors. These types of errors include forgetting to bind a control to a field in the row source, misspelling the property name or field name when creating the binding, or perhaps not including the field in the row source.

Binding errors may generate an error message in the debug output window so always check there if you experience odd behavior but no exception is thrown.

It will look similar to the following:. The offending control name appears in brackets at the start of the message and the exception details follow at the end of the message. The details may be generic such as a null reference exception or more detailed such as telling you which binding failed.

When using a DataSet as the data source for the data list control, be sure to use fully qualified member names in any bindings in the header and footer controls.

The header and footer controls are bound to the data source rather than an individual row and as such need the data member name specified in any data bindings. Accidentally binding two controls to the same field in the row source.

This problem will not usually generate any exceptions but may cause unexpected behavior such as one control assuming the value of another control when you make changes in the first control or a control losing its value when it loses the focus. Check the data bindings in the Bind method to ensure that they are binding to the correct fields and the correct properties in each control.

Not setting a unique binding context on controls that share a common data source within the same template. As noted earlier, each row template has its own binding context so controls in each one can share a common data source without conflicts i. However, as with any other form or user control, controls within the same template that share a common data source must have their own binding context.

For example, if you have two combo boxes on a template that share the same data source for their items, assign a new binding context to the BindingContext property in one or both of the combo boxes so that each can be set independently of the other within the same row. Setting a shared data source for the template's list controls after the template has been assigned to the data list control. If this occurs, the controls in the template combo boxes, list boxes, etc , may not show any items or will generate a null reference exception.

Be sure to set the shared data sources for such controls before assigning the template to the data list control. Also be sure to use the same key name so that the correct data source is retrieved from the data list's SharedDataSources property. Forgetting to call CommitChanges before saving the data source. If you save your data source i. Be sure to call the CommitChanges method on the data list or check the HasChanges property to ensure that any pending edits are pushed into the data source.

There is a bug in the. ListControls Library Documentation. Control Tutorials. Combo Box Controls Tutorial. DataList Control Tutorial. DataNavigator Control Tutorial. ExtendedTreeView Control Tutorial. General Information. Creating Header, Footer, and Row Templates. To create a new template control, follow these steps: Right click on the project in the Solution Explorer , select Add , Add User Control , enter a name for the new user control, and click Open to add it to the project.

Open the new user control in the designer and view the code for it. Forms Form Designer. Public Sub New ' This call is required by the Windows.

If Me. InitializeComponent ' Use the shared data source for the combo box cboState. ChangePolicyModified End Sub. AddBinding txtAddress, "Text" , "Address" ; this. AddBinding txtCity, "Text" , "City" ; this. AddBinding txtZip, "Text" , "Zip" ; this. Enabled And Me. Using the Templates. SetDataBinding dsAddresses.

Tables[ 0 ], null , typeof AddressRow ;. CommitChanges ; daAddresses. EventArgs ' We must commit any pending changes dlList. CommitChanges daAddresses. Update dsAddresses End Sub.

The Data List's Change Policy. Shared Control Data Sources in Templates. For example: C. Other constructor code Fill dtStates ; dlList. Add "States" , dtStates. Public Sub New ' Fill dtStates dlList.