SqlCeCommand.ExecuteScalar Method

Article
10/22/2007

Executes the query and returns the first column of the first row in the result set that is returned by the query. Extra columns or rows are ignored.

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

Syntax

'Declaration
Public Overrides Function ExecuteScalar As Object
'Usage
Dim instance As SqlCeCommand
Dim returnValue As Object

returnValue = instance.ExecuteScalar

public override Object ExecuteScalar ()

public:
virtual Object^ ExecuteScalar () override

public Object ExecuteScalar ()

public override function ExecuteScalar () : Object

Return Value

The first column of the first row in the result set.

Exceptions

Exception type	Condition
InvalidOperationException	Cannot execute a command within a transaction context that differs from the context in which the connection was originally enlisted.

Remarks

Use the ExecuteScalar method to retrieve a single value (such as an aggregate value) from a data source. This requires less code than using the ExecuteReader method, and then performing the operations necessary to generate the single value by using the data returned by a SqlCeDataReader.

Example

The following example creates a SqlCeCommand and then executes it using ExecuteScalar. The example is passed a string that is an SQL statement, which returns an aggregate result, and a string for connecting to the data source.

Dim cmd As New SqlCeCommand("SELECT col1 FROM myTable", conn)
cmd.Connection.Open()
Dim value As Object = cmd.ExecuteScalar()
conn.Close()

SqlCeCommand cmd = new SqlCeCommand("SELECT col1 FROM myTable", conn);
cmd.Connection.Open();
object value = cmd.ExecuteScalar();
conn.Close();

.NET Framework Security

Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see .

Platforms

Windows CE, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows XP Professional x64 Edition, Windows XP SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

Version Information

.NET Compact Framework

Supported in: 2.0, 1.0