Help with a OleDB connection string for excel files

Unfortunately, you can’t set ImportMixedTypes or TypeGuessRows from the connection string since those settings are defined in the registry. For the ACE OleDb driver, they’re stored at

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\14.0\Access Connectivity Engine\Engines\Excel

in the registry. So, you can simplify your connection string to:

conn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Nick\Desktop\Pricing2.xlsx;Extended Properties=""Excel 12.0 Xml;HDR=Yes;IMEX=1;""";

Once you set TypeGuessRows to 0 and ImportMixedTypes to Text in the registry, you should get the behavior you are expecting. You might, however, consider using a suitably large number like 1000 instead of zero if you find import performance to be less than ideal.

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