An excel spreadsheet can be used as a database. Use this connections tring (from www.connectionstrings.com):

"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties=""Excel 8.0;HDR=Yes;IMEX=1"""

notes:

"HDR=Yes;" indicates that the first row contains columnnames, not data
"IMEX=1;" tells the driver to always read "intermixed" data columns as text
TIP! SQL syntax: "SELECT * FROM [sheet1$]" - i.e. worksheet name followed by a "$" and wrapped in "[" "]" brackets.