Sharepoint 2013 : Business Connectivity Services - External Content Types

External content types (ECTs) are the linchpin for bridging connectivity between external data sources and SharePoint. Similar to regular content types in SharePoint , external content types represent an entity or classification of an object in your solution. An external content type contains fields, which are the attributes of the entity. If you have a background in software development, you may consider external content types analogous to code classes—classes describe objects, which are the concrete instances of a class.

Most content in SharePoint centralizes in content types because they represent a discrete portable entity in the SharePoint farm, which content owners may apply in different situations. Publishing, records management, document management, business intelligence, collaboration lists and libraries—they all leverage content types at the core to describe data schema in SharePoint. External content types integrate and operate in a similar fashion to that of internal content types, except that they describe entities of external data. For example, if you are aggregating personnel records from an external HR system, you might define an external content type that represents an employee, with fields for names, office location, and any other attribute of the employee.

The Business Connectivity Services Application page, will display external content types after you define them. To define a new external content type, you must use SharePoint Designer. The following steps demonstrate creation of an external content type, which represents an employee from an Adventure Works SQL database:

1. Open SharePoint Designer 2013 (SharePoint Designer 2013 is a free download: http://www.microsoft.com/en-us/download/details.aspx?id=30346).
2. Open your SharePoint 2013 site.
   
3. From the left navigation, click the External Content Types link, under the Site Objects left pane (see Figure 1).

   

   Figure 1. External Content Types in SharePoint Designer 2013

4. SharePoint Designer will show you any external content types you have in the site collection. In my case, I have none because I have not yet defined any.
5. Click the button for external content type in the new group within the ribbon.
6. On the new External Content Type page, give it a name and display name; I called mine Employee.
7. Set the Office Item type to the List type within SharePoint. I went with a generic list.
8. Decide if you want offline sync, meaning that SharePoint will allow you to read and update external data via cache when the external system is offline.
9. Click the link for the external system to discover your external system connection.
10. You should see a page like that in Figure 2.

    

    Figure 2. Connect to an external system

11. Click the Add Connection button.
12. Select the connection type. I chose SQL Server because I am demonstrating connection to the Adventure Works database.
13. Provide the connection details in the dialog box, as shown in Figure 3.

    

    Figure 3. SQL Server connection dialog for ECT creation

14. The dialog box for SQL Server database is not too helpful in that it will not enumerate the available databases for you.
15. Choose the security method for the connection—here you can use a Secure Store connection, or identity of the logged in user, or the impersonated user identity.
16. Choose Connect with Impersonated Windows Identity and provide the application ID from the Secure Store (default is to use the User’s Identity, as shown).
17. Click OK and provide the credentials you entered in the Secure Store.
18. You should see the connection to the data source created (Figure 4).

    

    Figure 4. SQL Server data source created

19. Expand the views node and right-click on the view for Employee.
20. You should see a list of operations to create—these are the Create, Read, Update, and Delete (CRUD) operations, used by SharePoint to access your data entity via the external content type—I chose all operations, to make life simple.
21. SharePoint Designer shows a wizard to configure the operations.
22. Click the Next button to configure the parameters for the entity (Figure 5). Here you get to choose the columns from the view and how they map to the external content type entity.

    

    Figure 5. Parameters Configuration in the ECT SQL Server Data Source Wizard

23. Click the E-mail Address column and then check the check box to map this field as an identifier.
24. Check the check box to show this column in the picker; this allows you to show values of this column in picker dialogs for choosing a specific entity.
25. Check the check box to show the value in picker dialogs for job title, last name, and first name columns.
26. The last page of the wizard shows the filter options that SharePoint Designer recommends for the data source (Figure 6).

    

    Figure 6. Filter page of the ECT SQL Server Data Source Wizard

27. Click the button to add a new filter.
28. Change the Data Source Element to the E-mail Address column.
29. Click the link to add the filter.
30. In the filter dialog, change the type to Limit and then click the OK button.
31. Enter the value 1000 in the Default Value.
32. Click the Finish button.

    Note  The wizard shows verbose warningand error messages for correct configuration of your external content type—SharePoint Designer disables the Finish button until you remedy all errors.

33. On the External Content Type details page, click the E-mail Address column in the Fields box.
34. Click the Set as Title icon on the ribbon.

At this point, you should have an external content type—I named mine Employee—some CRUD operations, and a limit of 1000 items returned. If you switch back to Central Administration and view the Business Connectivity Services Management page (Figure 7), you should see your external content type in the list.