Executes the query and returns the first column of the first row in the result set returned by the query. All other columns and rows are ignored.
Assembly: System.Data (in System.Data.dll)
Use the method to retrieve a single value (for example, an aggregate value) from a database. This requires less code than using the ExecuteReader method and performing the operations necessary to generate the single value using the data returned by a DbDataReader.
If the first column of the first row in the result set is not found, a null reference (Nothing in Visual Basic) is returned. If the value in the database is null, the query returns DBNull.Value.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)