SqlCeCommand.ExecuteScalar Method

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

Not applicable.

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();

Platforms

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

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

Version Information

.NET Framework

Supported in: 3.0

.NET Compact Framework

Supported in: 2.0, 1.0

See Also

Reference

SqlCeCommand Class
SqlCeCommand Members
System.Data.SqlServerCe Namespace