How to force ADO.Net to use only the System.String DataType in the readers TableSchema

Question

I am using an OleDbConnection to query an Excel 2007 Spreadsheet. I want force the OleDbDataReader to use only string as the column datatype.

The system is looking a

Answer 1

Check out the final answer on this page.

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Just noticed the page you refer to says the same thing ...

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Update:

The problem seems to be with the JET engine itself and not ADO. Once JET decides on the type, it sticks to it. Anything done after that has no effect; like casting the values to string in the SQL (e.g. Cstr([Column])) just results in an empty string being returned.

At this point (if there are no other answers) I'd opt for other methods: modifying the spreadsheet; modifying registry (not ideal since you will be messing with the settings for every other app the uses JET); Excel automation or a third party component that does not use JET.

If Automation option is to slow then maybe just use it to save the spreadsheet in a different format which is easier to handle.