Unexpected truncate Access MDB fields list

[Alex17]

I have Access .MDB file with 125 fields in one table. If I open this MDB I have seen all 125 fields. If I open the same table by OpenSource MDB Viewer I see data in 125 fields, but catalog of fields is truncated on 50 fields.


I need to open this MDB with my .NET Framework 4.8 program. I make this job by OleDb.OleDbConnection provider with this connection string

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=G:\my.mdb

Unexpectedly, I can see only first 50 fields of data. Any attempt to read by ADO.NET next field from 50 to 125 is failed.

Input6
 at System.Data.ProviderBase.FieldNameLookup.GetOrdinal(String fieldName)
 at System.Data.OleDb.OleDbDataReader.GetOrdinal(String name)
 at System.Data.OleDb.OleDbDataReader.get_Item(String name)
 at AtiConverter.Module1._Closure$__._Lambda$__12-4(OleDbDataReader X) in G:\Projects\ATI\Access\Converter1\Converter1\AccessRead.vb:line 63
 at AtiConverter.RawSqlQuery.RawSqlQuery[T](OleDbConnection Connection, String SqlQuery, Func`2 RowMapperFunc, Boolean NeedPrint) in G:\Projects\ATI\Access\Converter1\Converter1\RawSqlQuery.vb:line 23

I'm use ordinary Win 11 with last update.

[June7]

Cross post https://stackoverflow.com/questions/...db-fields-list

[isladogs]

The 50 field limit may be a limitation of the MDB viewer you are using.
What happens if you click the Add 50 Rows button again?

Suggest you contact the developer (if the app is still available for download)
But why use an MDB viewer rather than open it in Access (full version or runtime)?

NOTE that there are no equivalent ACCDB viewers to the best of my knowledge

[Alex17]

Ha-ha, thank youisladogs.
I'm idiot. If I click Add 50 row twice, I can see full list of columns.



But my issue is deeper. MDB viewer is only small additional utilities to visualize data. I'm programmer and my job is read data from Access DB for further processing.
I try to read by ordinary ADO.NET Logic. ADO NET Reader and While RDR.READ



Maybe, there is special operation when I need to read fields after 50 column. It's possible only 50 column is loading automatically and next 50 need to load by something special operation.
I try to use JET provider and ACE provider, but I have no result - only 50 column is loaded.

[Alex17]

I'm sorry. It's a my program mistake. ACE provider CAN read more than 50 columns of data. Mistake was in my RowMapperFunction on the screen above, because my program has sophisticated logic and this RowMapping function was build by sophisticated and complex way. Additionally I have seen strange restriction of 50 columns in MDB viewer and go to forum instead going to my own code.

[isladogs]

Glad you have a solution!