How to use existing SharePoint Data Source in Visual WebPart in Visual Studio

Question

I want to create a SharePoint Visual Web Part using Visual Studio, which will query SQL database and will display some data (e.g. Latest News from Database)
I already have a SQL Data Source (rsds file) in SharePoint. Can i use this rsds to connect SQL database for my Visual Web Part ?

Answer 1

I will use web.config as last option but can you please explain how BdcService will connect external SQL database.
What if I use SharePoint property to store connectivity information and all web parts will use it to make connection string?
Following code returns 0 entities
// Get reference to BDC Service
BdcService service =
SPFarm.Local.Services.GetValue<BdcService>();
// Get MetaData Catalog
IMetadataCatalog catalog = service.GetDatabaseBackedMetadataCatalog(SPServiceContext.Current);
// Some heading for the literal control
string dbData =
"<h1>Lob Systems and Entities … </h1> " +
"</br>";
// Get all the external content types from the meta data catalog
foreach (IEntity
ect in catalog.GetEntities("*"))
// Add external content type’s name and lob system name to the literal control
dbData += ect.Name +
"," + ect.GetLobSystem().Name +
"</br>";
ltMsg.Text = dbData;