public object Execute(Expression expression)
{
IDbCommand cmd = DbProvider.GetCommand();
SQLPredicate sql = Translate(expression);
LogQuery(sql.Sql, sql.Parameters);
cmd.CommandText = sql.Sql;
sql.SetParameters(cmd);
// cmd.Connection = DbProvider.Connection; eliminating this because DbProvider already passes its connection to cmd
try
{
IDataReader reader = cmd.ExecuteReader();
Type elementType = TypeSystem.GetElementType(expression.Type);
//TODO: for select to work properly, we need to identify whether the elementType is an IEnumerable or not
if (!typeof(IQueryable).IsAssignableFrom(expression.Type))
{
//This is to handle Count method
if (elementType == typeof(int))
{
reader.Read();
int result = Convert.ToInt32(reader[0] == DBNull.Value ? 0 : reader[0]);
reader.Dispose();
return(result);
}
//Sum method
if (elementType == typeof(double))
{
reader.Read();
double result = Convert.ToDouble(reader[0] == DBNull.Value ? 0 : reader[0]);
reader.Dispose();
return(result);
}
//Any method
if (elementType == typeof(bool))
{
reader.Read();
bool result = Convert.ToBoolean(reader[0]);
reader.Dispose();
return(result);
}
}
if (elementType.IsPrimitive || elementType == typeof(string))
{
return(Activator.CreateInstance(
typeof(VariableReader <>).MakeGenericType(elementType),
BindingFlags.Instance | BindingFlags.NonPublic, null,
new object[] { reader },
null));
}
return(Activator.CreateInstance(
typeof(ObjectReader <>).MakeGenericType(elementType),
BindingFlags.Instance | BindingFlags.NonPublic, null,
new object[] { reader },
null));
//}
}
catch (Exception e)
{
//TODO: Delete this in oproduction
throw new Exception(e.Message + "." + " Query: " + cmd.CommandText);
}
//}
}
