public void Select_MultipleResultSets()
{
var batchCmdBuilder = new DbBatchCommandBuilder(DbAdapter.CommandBuilder.DbFactory);
batchCmdBuilder.BeginBatch();
batchCmdBuilder.GetSelectCommand(new Query("companies"));
batchCmdBuilder.GetSelectCommand(new Query("contacts"));
var selectMultipleCmd = batchCmdBuilder.EndBatch();
(var companies, var contacts) = DbAdapter.Select(selectMultipleCmd).ExecuteReader((rdr) => {
var companiesRes = new DataReaderResult(rdr).ToList <CompanyModelAnnotated>();
rdr.NextResult();
var contactsRes = new DataReaderResult(rdr).ToList <ContactModel>();
return(companiesRes, contactsRes);
});
Assert.Equal(2, companies.Count);
Assert.Equal(5, contacts.Count);
}
public static void RunSelectMultipleResultSet(DbContext dbContext)
{
// lets generate several selects in one command
var batchCmdBuilder = new DbBatchCommandBuilder(dbContext.DbFactory);
Console.WriteLine("Composing 2 selects in one DbCommand (multiple result sets)");
batchCmdBuilder.BeginBatch();
batchCmdBuilder.GetSelectCommand(new Query("Customers", (QField)"Country" == (QConst)"Germany"));
batchCmdBuilder.GetSelectCommand(new Query("Orders",
new QConditionNode((QField)"CustomerID", Conditions.In,
new Query("Customers.c", (QField)"c.Country" == (QConst)"Germany").Select("c.CustomerID")
)
));
var multiSelectCmd = batchCmdBuilder.EndBatch();
multiSelectCmd.Connection = dbContext.Connection;
RecordSet customerRS = null;
RecordSet orderRS = null;
dbContext.Connection.Open();
try {
using (var rdr = multiSelectCmd.ExecuteReader()) {
customerRS = RecordSet.FromReader(rdr);
if (rdr.NextResult())
{
orderRS = RecordSet.FromReader(rdr);
}
}
} finally {
dbContext.Connection.Close();
}
Console.WriteLine($"Loaded {customerRS.Count} customers and {orderRS.Count} their orders from one data reader");
}