SqlConnection nwindConn = new SqlConnection("Data Source=localhost;Integrated Security=SSPI;Initial Catalog=northwind");SqlCommand salesCMD = new SqlCommand("SalesByCategory", nwindConn);
salesCMD.CommandType = CommandType.StoredProcedure;SqlParameter myParm = salesCMD.Parameters.Add("@CategoryName", SqlDbType.NVarChar, 15);
myParm.Value = "Beverages";nwindConn.Open();SqlDataReader myReader = salesCMD.ExecuteReader();Console.WriteLine("{0}, {1}", myReader.GetName(0), myReader.GetName(1));while (myReader.Read())
{
Console.WriteLine("{0}, ${1}", myReader.GetString(0), myReader.GetDecimal(1));
}myReader.Close();
nwindConn.Close();
salesCMD.CommandType = CommandType.StoredProcedure;SqlParameter myParm = salesCMD.Parameters.Add("@CategoryName", SqlDbType.NVarChar, 15);
myParm.Value = "Beverages";nwindConn.Open();SqlDataReader myReader = salesCMD.ExecuteReader();Console.WriteLine("{0}, {1}", myReader.GetName(0), myReader.GetName(1));while (myReader.Read())
{
Console.WriteLine("{0}, ${1}", myReader.GetString(0), myReader.GetDecimal(1));
}myReader.Close();
nwindConn.Close();
command
open
close
salesCMD.CommandType = CommandType.StoredProcedure;SqlParameter myParm = salesCMD.Parameters.Add("@CategoryName", SqlDbType.NVarChar, 15);
myParm.Value = "Beverages";nwindConn.Open();SqlDataReader myReader = salesCMD.ExecuteReader();Console.WriteLine("{0}, {1}", myReader.GetName(0), myReader.GetName(1));while (myReader.Read())
{
Console.WriteLine("{0}, ${1}", myReader.GetString(0), myReader.GetDecimal(1));
}myReader.Close();
nwindConn.Close();OleDbOleDbConnection nwindConn = new OleDbConnection("Provider=SQLOLEDB;Data Source=localhost;Integrated Security=SSPI;" +
"Initial Catalog=northwind");OleDbCommand salesCMD = new OleDbCommand("SalesByCategory", nwindConn);
salesCMD.CommandType = CommandType.StoredProcedure;OleDbParameter myParm = salesCMD.Parameters.Add("@CategoryName", OleDbType.VarChar, 15);
myParm.Value = "Beverages";nwindConn.Open();OleDbDataReader myReader = salesCMD.ExecuteReader();Console.WriteLine("\t{0}, {1}", myReader.GetName(0), myReader.GetName(1));while (myReader.Read())
{
Console.WriteLine("\t{0}, ${1}", myReader.GetString(0), myReader.GetDecimal(1));
}myReader.Close();
nwindConn.Close();Parameter 对象可以使用 Parameter 构造函数来创建,或通过调用 Command 的 Parameters 集合的 Add 方法来创建。Parameters.Add 会将构造函数参数或现有 Parameter 对象用作输入。在将 Parameter 的 Value 设置为空引用时,请使用 DBNull.Value。对于 Input 参数之外的参数,必须设置 ParameterDirection 属性来指定参数类型是 InputOutput、Output 还是 ReturnValue。以下示例显示创建 Input、Output 和 ReturnValue 参数之间的差异。