SqlCommand.ExecuteScalar Method

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.

Namespace: System.Data.SqlClient
Assembly: System.Data (in system.data.dll)

Public Overrides Function ExecuteScalar As Object
Dim instance As SqlCommand
Dim returnValue As Object

returnValue = instance.ExecuteScalar
public Object ExecuteScalar ()
public override function ExecuteScalar () : Object
Not applicable.

Return Value

The first column of the first row in the result set, or a null reference (Nothing in Visual Basic) if the result set is empty.

Exception typeCondition


An exception occurred while executing the command against a locked row. This exception is not generated when you are using Microsoft .NET Framework version 1.0.

Use the ExecuteScalar method to retrieve a single value (for example, an aggregate value) from a database. This requires less code than using the ExecuteReader method, and then performing the operations that you need to generate the single value using the data returned by a SqlDataReader.

A typical ExecuteScalar query can be formatted as in the following C# example:

 cmd.CommandText = "SELECT COUNT(*) FROM dbo.region";
 Int32 count = (Int32) cmd.ExecuteScalar();

The following example creates a SqlCommand and then executes it using ExecuteScalar. The example is passed a string representing a new value to be inserted into a table, and a string to use to connect to the data source. The function returns the new Identity column value if a new row was inserted, 0 on failure.

Public Function AddProductCategory( _
  ByVal newName As String, ByVal connString As String) As Integer
    Dim newProdID As Int32 = 0
    Dim sql As String = _
     "INSERT INTO Production.ProductCategory (Name) VALUES (@Name); " _
       & "SELECT CAST(scope_identity() AS int);"

    Using conn As New SqlConnection(connString)
        Dim cmd As New SqlCommand(sql, conn)
        cmd.Parameters.Add("@Name", SqlDbType.VarChar)
        cmd.Parameters("@Name").Value = newName
            newProdID = Convert.ToInt32(cmd.ExecuteScalar())
        Catch ex As Exception
        End Try
    End Using

    Return newProdID
End Function

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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