Executes the query, and returns the first column of the first row in the result set returned by the query. Additional columns or rows are ignored.
Assembly: System.Data (in System.Data.dll)
'Declaration Public Overrides Function ExecuteScalar As Object 'Usage Dim instance As OleDbCommand Dim returnValue As Object returnValue = instance.ExecuteScalar()
Return ValueType: System.Object
The first column of the first row in the result set, or a null reference if the result set is empty.
Cannot execute a command within a transaction context that differs from the context in which the connection was originally enlisted.
Use the method to retrieve a single value, for example, an aggregate value, from a data source. This requires less code than using the ExecuteReader method, and then performing the operations that are required to generate the single value using the data returned by an OleDbDataReader.
A typical query can be formatted as in the following C# example:
CommandText = "SELECT COUNT(*) FROM region"; Int32 count = (int32) ExecuteScalar();
The following example creates an OleDbCommand and then executes it using . The example is passed a string that is an SQL statement that returns an aggregate result, and a string to use to connect to the data source.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.