Creating external content types
Once the external system definition is defined, you can now create
an ECT and specify the CRUD operations that you wish to execute on that
external system. Many organizations use ECTs rather than the Data
Sources gallery for security and logistic reasons. The ECT can be
defined once and stored centrally in the BDC metadata store, but used
many times for all sites and site collections depending on the
permission settings of the ECT. The schema and authentication methods
need only be explained to a small number of ECT designers. This is as
opposed to the Data Sources gallery, where the data source definition
would have to be created for each site where you want to use the
external content.
Follow these steps to create an ECT using SharePoint Designer:
-
In the ECT Summary view, ensure that the ECT has a name, and if the
external content is to be displayed in Outlook 2013, configure the
Office item type as Appointment, Contact, Task, or Post. Switch to the
Operations view of the ECT. -
In the Data Source Explorer, expand the external system node by clicking the plus sign (+) to the right of the name.
If the data source is a database, expand Tables, Views, or Routines. -
Right-click the table you want to create a BDC model for and then click the operations you want to create.
Depending on the operations exposed by the external system, you can
add the operations create, read item, update, delete, and read list, as
shown next.
A
three-page operations wizard opens, where each page contains a section
that displays issues, warnings, and errors as you configure the
operations. The three pages are:
-
Operation properties
. Use this page to set the operation name, operation
display name, and operation type. For a database external system, you
can create all operations. If you choose this option, then the
operation properties are generated automatically and the operation
names will be Create, Read Item, Update, Delete, and Read List.
When you create an External List from an ECT, then a view is created
for each Read List operation. You may consider modifying the
automatically generated names for the Read List operations so that they
are meaningful to users of the external list. -
Parameters
. Use this page to select those fields, known as elements,
you wish to use in your SharePoint solution. You can modify each data
source element, including the identifier name, the field name, and the
name of the field when it is displayed in the browser. By default, all
fields will be shown in the external item picker when adding an
external data column to a list or library. If the table, view, or
routine returns a large number of fields, displaying them all in the
external item picker may confuse users. Therefore, it is best to select
a small set of elements that best describes an item.
If you selected an Office item type on the Summary View, you will
use this page to map the external content data fields to Office
properties. The Office mapping form is part of the Read Item operation,
and therefore, if you wish to modify these settings once an ECT is
created, modify the return parameter properties of the Read Item
operation. You also change the Office item type on the Summary page
once an ECT is created. -
Filter parameters
. Use this page to add your own throttling conditions
to your solution; this will optimize the time taken to return the data
from the external system. Remember, external content is not saved in
the BCS database, but is retrieved by the BDC server run time when
needed.
The filter types available are Comparison, Limit, Page Number,
Timestamp, and Wildcard. For string data types, use the Wildcard filter
type because this will internally translate to a like clause in queries
to get the data.
BCS throttling is enabled by default to prevent Denial of Service
(DoS) attacks. You are most likely to see the effect of this feature if
no limit filter was created and when the BCS run time attempted to
retrieve data from the external system it timed out due to the large
amount of data it was trying to retrieve.
-
Click Finish and then Save.
This will create in the BDC metadata store an external system named
<databasename> if this is the first ECT created for the external
system, and an ECT with the name you typed in step 1.
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