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
abstract ExecuteScalar : unit -> Object
override ExecuteScalar : unit -> Object
public override function ExecuteScalar() : Object
Return Value
Type: System.Object
The first column of the first row in the result set.
Implements
Exceptions
| Exception | 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.
Examples
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();