SQL IF EXISTS statement in C#

OleDbConnection database;

string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=PCAN.mdb";
database = new OleDbConnection(connectionString);
database.Open();

string query = @

"IF EXISTS (SELECT * FROM VEHICLE_SPEED)
 BEGIN
 INSERT INTO VEHICLE_SPEED (SPD, SPEED_VALUE) VALUES (@SPD, @SPEED_VALUE)   
 END
 ELSE 
 BEGIN
 CREATE TABLE VEHICLE_SPEED (SPD INT, SPEED_VALUE NVARCHAR(10))   
 INSERT INTO VEHICLE_SPEED (SPD, SPEED_VALUE) VALUES (@SPD, @SPEED_VALUE)
 END";
 
 int number = 0;
 OleDbCommand SQLQuery2 = new OleDbCommand(query, database);
 // ... other parameters
 SQLQuery2.Parameters.AddWithValue("@SPD", number++);
 SQLQuery2.Parameters.AddWithValue("@SPEED_VALUE", txtVehSpd.Text);
 SQLQuery2.ExecuteNonQuery();