c# - 如何将信息更新到数据库wpf

Question

单击按钮时，我想使用以下代码进行更新。但我想更新additionalInformation唯一的。我该怎么做呢？

   public static void Update(Resident resident, SqlConnection connection, SqlTransaction                  transaction)
{
    StringBuilder sqlString = new StringBuilder();
    SqlCommand command;

    sqlString.Append("UPDATE [Resident] SET ");
    sqlString.Append("title = @title, ");
    sqlString.Append("firstName = @firstName, ");
    sqlString.Append("surname = @surname, ");
    sqlString.Append("dateOfBirth = @dateOfBirth, ");
    sqlString.Append("photo = @photo, ");
    sqlString.Append("doctorID = @doctorID, ");
    sqlString.Append("roomID = @roomID, ");
    sqlString.Append("allergies = @allergies, ");
    sqlString.Append("additionalInformation = @additionalInformation ");
    sqlString.Append("WHERE residentID = @residentID ");
    command = new SqlCommand(sqlString.ToString(), connection);
    if ((transaction != null)) command.Transaction = transaction;

    command.Parameters.Add("@residentID", SqlDbType.Int).Value = resident.ResidentID;
    command.Parameters.Add("@title", SqlDbType.VarChar, 50).Value = Helper.GetValue(resident.Title);
    command.Parameters.Add("@firstName", SqlDbType.VarChar, 100).Value = Helper.GetValue(resident.FirstName);
    command.Parameters.Add("@surname", SqlDbType.VarChar, 100).Value = Helper.GetValue(resident.Surname);
    command.Parameters.Add("@dateOfBirth", SqlDbType.DateTime).Value = Helper.GetValue(resident.DateOfBirth);
    command.Parameters.Add("@photo", SqlDbType.Image, 2147483647).Value = Helper.GetValue(resident.Photo);
    command.Parameters.Add("@doctorID", SqlDbType.Int).Value = resident.Doctor.DoctorID;
    command.Parameters.Add("@roomID", SqlDbType.Int).Value = resident.Room.RoomID;
    command.Parameters.Add("@allergies", SqlDbType.NText).Value = resident.Allergies;
    command.Parameters.Add("@additionalInformation", SqlDbType.NText).Value = resident.addtionalInformation;
    int rowsAffected = command.ExecuteNonQuery();

    if (!(rowsAffected == 1))
    {
        throw new Exception("An error has occurred while updating Resident details.");
    }
}

Answer 1

您可以再传递一个参数，表明您只想更新addidionalInformation，例如：

public static void Update(Resident resident, SqlConnection connection, SqlTransaction transaction, bool updateOnlyAdditionalInformation)
{
    StringBuilder sqlString = new StringBuilder();
    SqlCommand command;

    sqlString.Append("UPDATE [Resident] SET ");

    if (!updateOnlyAdditionalInformation)
    {
      sqlString.Append("title = @title, ");
      sqlString.Append("firstName = @firstName, ");
      sqlString.Append("surname = @surname, ");
      sqlString.Append("dateOfBirth = @dateOfBirth, ");
      sqlString.Append("photo = @photo, ");
      sqlString.Append("doctorID = @doctorID, ");
      sqlString.Append("roomID = @roomID, ");
      sqlString.Append("allergies = @allergies, ");
    }

    sqlString.Append("additionalInformation = @additionalInformation ");
    sqlString.Append("WHERE residentID = @residentID ");
    command = new SqlCommand(sqlString.ToString(), connection);
    if ((transaction != null)) command.Transaction = transaction;

    command.Parameters.Add("@residentID", SqlDbType.Int).Value = resident.ResidentID;
    command.Parameters.Add("@additionalInformation", SqlDbType.NText).Value = resident.addtionalInformation;

    if (!updateOnlyAdditionalInformation)
    {
      command.Parameters.Add("@title", SqlDbType.VarChar, 50).Value = Helper.GetValue(resident.Title);
      command.Parameters.Add("@firstName", SqlDbType.VarChar, 100).Value = Helper.GetValue(resident.FirstName);
      command.Parameters.Add("@surname", SqlDbType.VarChar, 100).Value = Helper.GetValue(resident.Surname);
      command.Parameters.Add("@dateOfBirth", SqlDbType.DateTime).Value = Helper.GetValue(resident.DateOfBirth);
      command.Parameters.Add("@photo", SqlDbType.Image, 2147483647).Value = Helper.GetValue(resident.Photo);
      command.Parameters.Add("@doctorID", SqlDbType.Int).Value = resident.Doctor.DoctorID;
      command.Parameters.Add("@roomID", SqlDbType.Int).Value = resident.Room.RoomID;
      command.Parameters.Add("@allergies", SqlDbType.NText).Value = resident.Allergies;
    }

    int rowsAffected = command.ExecuteNonQuery();

    if (!(rowsAffected == 1))
    {
        throw new Exception("An error has occurred while updating Resident details.");
    }
}