透過引數傳遞:

string sql = "select count(*) from zhuce where username=@username and pwd=@pwd and type = @type";

SqlConnection conn = new SqlConnection(Common.Context.SqlManager.CONN_STRING);

conn.Open();

SqlCommand cmd = new SqlCommand(sql, conn);

cmd.Parameters.Add("@username",SqlDbType.VarChar，30);

cmd.Parameters.Add("@pwd",SqlDbType.VarChar，30);

cmd.Parameters.Add("@type",SqlDbType.VarChar，10);

cmd.Parameters["@username"].Value = username;

cmd.Parameters["@pwd"].Value = pwd;

cmd.Parameters["@type"].Value = power.Text;

int count = Convert.ToInt32(cmd.ExecuteScalar());

conn.Close();