.Net 4.5 / WPF / MVVM / ADO.Net / Oracle 11g / Oracle.DataAccess.Client
Using : IDataReader Interface
So, I have sealed BusinessObject builder class, which takes in a DataReader object, converts the data inside each field in that DataReader based on PropertyMap - the PropertyMap is retrieved from a class - and returns a ListItem.
This ListItem is then added to a List and the List is then used to process the data, display the data etc on the View.
The whole process is working perfect with in other places inside my application and today I was trying to use the BusinessObject builder process to convert a new set of records to a List and use it in my DashBoard.
The propertymap for this entiry is as below.
- pinfo Count = 9 System.Collections.Generic.Dictionary<string,System.Reflection.PropertyInfo>
+ [0] {[LATEST_LOAD_TIME, System.DateTime LATEST_LOAD_TIME]}
+ [1] {[LAST_DELIVERY, System.DateTime LAST_DELIVERY]}
+ [2] {[MAXVALDATE, System.DateTime MAXVALDATE]}
+ [3] {[MINVALDATE, System.DateTime MINVALDATE]}
+ [4] {[COMPLETED, Int32 COMPLETED]}
+ [5] {[FAILED, Int32 FAILED]}
+ [6] {[IN_PROGRESS, Int32 IN_PROGRESS]}
+ [7] {[NOT_STARTED, Int32 NOT_STARTED]}
+ [8] {[TOTAL, Int32 TOTAL]}
But, as soon as the process hits the if () clause below
for (int i = 0; i < dataReader.FieldCount; i++)
{
if (dataReader.GetValue(i) != DBNull.Value)
{
try
{
it throws an System.InvalidOperationException exception. See the full exception details below.
+ dataReader {Oracle.DataAccess.Client.OracleDataReader} System.Data.IDataReader {Oracle.DataAccess.Client.OracleDataReader}
- dataReader.GetValue(i) 'dataReader.GetValue(i)' threw an exception of type 'System.InvalidOperationException' object {System.InvalidOperationException}
- base {"Operation is not valid due to the current state of the object."} System.SystemException {System.InvalidOperationException}
- base {"Operation is not valid due to the current state of the object."} System.Exception {System.InvalidOperationException}
+ Data {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
HelpLink null string
HResult -2146233079 int
+ InnerException null System.Exception
Message "Operation is not valid due to the current state of the object." string
Source "Oracle.DataAccess" string
StackTrace " at Oracle.DataAccess.Client.OracleDataReader.GetValue(Int32 i)" string
- TargetSite {System.Object GetValue(Int32)} System.Reflection.MethodBase {System.Reflection.RuntimeMethodInfo}
+ [System.Reflection.RuntimeMethodInfo] {System.Object GetValue(Int32)} System.Reflection.RuntimeMethodInfo
- base {System.Object GetValue(Int32)} System.Reflection.MemberInfo {System.Reflection.RuntimeMethodInfo}
+ CustomAttributes Count = 0 System.Collections.Generic.IEnumerable<System.Reflection.CustomAttributeData> {System.Collections.ObjectModel.ReadOnlyCollection<System.Reflection.CustomAttributeData>}
+ DeclaringType {Name = "OracleDataReader" FullName = "Oracle.DataAccess.Client.OracleDataReader"} System.Type {System.RuntimeType}
MemberType Method System.Reflection.MemberTypes
MetadataToken 100665607 int
+ Module {Oracle.DataAccess.dll} System.Reflection.Module {System.Reflection.RuntimeModule}
Name "GetValue" string
+ ReflectedType {Name = "OracleDataReader" FullName = "Oracle.DataAccess.Client.OracleDataReader"} System.Type {System.RuntimeType}
Attributes FamANDAssem | Family | Virtual | HideBySig System.Reflection.MethodAttributes
CallingConvention Standard | HasThis System.Reflection.CallingConventions
ContainsGenericParameters false bool
IsAbstract false bool
IsAssembly false bool
IsConstructor false bool
IsFamily false bool
IsFamilyAndAssembly false bool
IsFamilyOrAssembly false bool
IsFinal false bool
IsGenericMethod false bool
IsGenericMethodDefinition false bool
IsHideBySig true bool
IsPrivate false bool
IsPublic true bool
IsSecurityCritical true bool
IsSecuritySafeCritical true bool
IsSecurityTransparent false bool
IsSpecialName false bool
IsStatic false bool
IsVirtual true bool
+ MethodHandle {System.RuntimeMethodHandle} System.RuntimeMethodHandle
MethodImplementationFlags IL System.Reflection.MethodImplAttributes
+ Non-Public members
+ Static members
+ Non-Public members
I know the exception says
Message "Operation is not valid due to the current state of the object."
and I thought the DataReader might be closed, but it is not. See below the status
- dataReader {Oracle.DataAccess.Client.OracleDataReader} System.Data.IDataReader {Oracle.DataAccess.Client.OracleDataReader}
+ [Oracle.DataAccess.Client.OracleDataReader] {Oracle.DataAccess.Client.OracleDataReader} Oracle.DataAccess.Client.OracleDataReader
Depth 0 int
IsClosed false bool
RecordsAffected -1 int
- Results View Expanding the Results View will enumerate the IEnumerable
- [0] {System.Data.Common.DataRecordInternal} object {System.Data.Common.DataRecordInternal}
- base {System.Data.Common.DataRecordInternal} System.Data.Common.DbDataRecord {System.Data.Common.DataRecordInternal}
FieldCount 9 int
FieldCount 9 int
Also, please see that the DataReader record does contain values
- _values {object[9]} object[]
[0] 0 object {decimal}
[1] 0 object {decimal}
[2] 0 object {decimal}
[3] 0 object {decimal}
[4] 1502 object {decimal}
+ [5] {} object {System.DBNull}
+ [6] {} object {System.DBNull}
+ [7] {5/5/2015 12:00:00 AM} object {System.DateTime}
+ [8] {4/30/2015 12:00:00 AM} object {System.DateTime}
+ [1] {System.Data.Common.DataRecordInternal} object {System.Data.Common.DataRecordInternal}
+ [2] {System.Data.Common.DataRecordInternal} object {System.Data.Common.DataRecordInternal}
Initially the first item in the data record was of type DateTime and I thought the error might be because of that. So I changed the column ordinal to put a record of type int as the first item - but the exception is still thrown.
I think it has to do something with the GetValue() method, but not sure.
Anyone have any idea what possibly might be the issue and any advice / help?
Sorry for the long code / exception samples, but don't want to miss out any details...
GetValue is supposed to return DBNull for null values but try this
if (!dataReader.isDBNull(i))
{
...
}
or try this syntax
if (!DBNull.Value.Equals(dataReader.GetValue(i)))