Using Dot Notation in the Business Data Connectivity (BDC) Service
Applies to: SharePoint Server 2010
In this article
Example1: Refer to a field of a complex type
Example2: Access collections
Example3: Refer to fields that have special characters
A data structure returned by an external system can contain complex structures with multiple levels of data elements. In Business Data Connectivity (BDC) service, each level of data elements can be accessed by using the dot notation. Dot notation is a representation of the data elements similar to accessing data elements in C#. Each data element is accessed by providing their parent data element and the name of the data element if the containing data element is a structure, or the index of the data element, if the containing element is a collection. Following are some examples of how to use dot notation.
Example1: Refer to a field of a complex type
Consider a Customer structure is an external item with the following fields:
CustomerID
Name
PhoneNumber
Address
Street
City
State
Zip
The Address field is a complex type. Let's assume that you want to display the following fields from the Customer external item:
Name
PhoneNumber
City
State
In this case, you can get these fields by using the indexer in the IEntityInstance interface as shown in the following code.
IEntityInstance customerItem = customerEntity.FindSpecific (...);
customerItem["Name"]
customerItem["PhoneNumber"]
customerItem["Address.City"]
customerItem["Address.State"]
Example2: Access collections
You can also refer to members inside of collections by using BDC. Consider a Customer structure with the following fields:
CustomerID
Name
PhoneNumber
Addresses (this is a collection of Address elements)
Address
Street
City
State
Zip
The customer structure in this example contains an Address collection. Let's assume that the first address in the collection is the primary address and that you want to display the following fields from the Customer external item:
CustomerID
Name
PhoneNumber
PrimaryAddressCity
PrimaryAddressState
In this case, in the return parameter of the SpecificFinder method instance, you can refer to the City and State subfields of the Customer structure as shown in the following code.
Customer.Addresses[0].City
Customer.Addresses[0].State
Example3: Refer to fields that have special characters
If the name contains one of the following special characters: backslash ("\"), period ("."), or bracket ("["), you must escape the special character with "\".
Consider a Customer structure with the following fields:
CustomerID
Name
PhoneNumber
Address
Street
House\PropertyNo
City
State
Zip
The field "House\PropertyNo" contains the following special character: "\". Let's assume that you want to display the following fields from the Customer external item:
CustomerID
Name
PhoneNumber
House\PropertyNo
City
State
In this case, in the return parameter of the SpecificFinder method instance, you can refer to House\PropertyNo subfield of the Customer structure as shown in the following code:
Customer.Address.House\\PropertyNo