public void EntityDataLoader_CommandTreeBuilder()
{
var connString = "NorthwindObjectContext";
var asm = typeof(NorthwindObjectContext).Assembly;
var workspace = MetadataWorkspaceHelper.GetMetadataWorkspace(connString, asm);
var entitySet = workspace.GetItems(DataSpace.SSpace)
.OfType <EntityContainer>()
.First()
.BaseEntitySets
.OfType <EntitySet>()
.First();
var tree = CommandTreeBuilder.CreateSelectAll(workspace, entitySet);
var query = tree as DbQueryCommandTree;
query.Should().NotBeNull();
var scan = query.Query as DbScanExpression;
scan.Should().NotBeNull();
scan.Target.Should().Be(entitySet);
}
/// <summary>
/// Creates a data reader that retrieves the initial data from the database.
/// </summary>
/// <returns>
/// The data reader.
/// </returns>
protected override IDataReader CreateDataReader()
{
// Build a command tree, which queries all records
DbCommandTree commandTree =
CommandTreeBuilder.CreateSelectAll(this.workspace, this.entitySet);
// Get the provider services of the wrapped connection
DbProviderServices providerServices =
DbProviderServices.GetProviderServices(this.connection.StoreConnection);
// Get current manifest token
string manifestToken =
providerServices.GetProviderManifestToken(this.connection.StoreConnection);
// Get provider manifest
DbProviderManifest providerManifest =
providerServices.GetProviderManifest(manifestToken);
// Create a command definition from the command tree
DbCommandDefinition commandDefinition =
providerServices.CreateCommandDefinition(providerManifest, commandTree);
// Compile command
DbCommand command = commandDefinition.CreateCommand();
// Setup command
command.Connection = this.connection.StoreConnection;
// Execute
DbDataReader reader = command.ExecuteReader();
return(reader);
}
