DB2Command.ExecuteScalar Method

Syntax

[Visual Basic]
NotOverridable Public Function ExecuteScalar() As Object
[C#]
public object ExecuteScalar();
[C++]
public: __sealed Object* ExecuteScalar();
[JScript]
public function ExecuteScalar() : Object;

Return value

The first column of the first row in the resultset.

Remarks

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 necessary to generate the single value from the data returned by a   DB2®DataReader .

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

CommandText = "select count(*) as NumberOfEmployee from EMPLOYEE";
Int count = (int) ExecuteScalar();

Example

[Visual Basic, C#] The following example creates a DB2Command and then executes it using ExecuteScalar. 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 database.

[Visual Basic]
Public Sub CreateMyDB2Command(myScalarQuery As String, 
    myConnection As DB2Connection)
    Dim myCommand As New DB2Command(myScalarQuery, myConnection)
    myCommand.Connection.Open()
    Dim qryValue As object = myCommand.ExecuteScalar()
    myConnection.Close()
End Sub 'CreateMyDB2Command

[C#]
public void CreateMyDB2Command(string myScalarQuery, DB2Connection myConnection)
 {
    DB2Command myCommand = new DB2Command(myScalarQuery, myConnection);
    myCommand.Connection.Open();
    object qryValue = myCommand.ExecuteScalar();
    myConnection.Close();
 }