Accessing Excel Spreadsheet with C# occasionally returns blank value for some cells

Question

I need to access an excel spreadsheet and insert the data from the spreadsheet into a SQL Database. However the Primary Keys are mixed, most are numeric and some are alpha-n

Answer 1

Solution:

Connection String:

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=FilePath;Extended Properties="Excel 8.0;HDR=Yes;IMEX=1";

1. HDR=Yes; indicates that the first row contains columnnames, not data. HDR=No; indicates the opposite.

2. IMEX=1; tells the driver to always read "intermixed" (numbers, dates, strings etc) data columns as text. Note that this option might affect excel sheet write access negative.

SQL syntax SELECT * FROM [sheet1$]. I.e. excel worksheet name followed by a $ and wrapped in [ ] brackets.

Important:

• Check out the [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Excel] located registry REG_DWORD "TypeGuessRows". That's the key to not letting Excel use only the first 8 rows to guess the columns data type. Set this value to 0 to scan all rows. This might hurt performance.

• If the Excel workbook is protected by a password, you cannot open it for data access, even by supplying the correct password with your connection string. If you try, you receive the following error message: "Could not decrypt file."