我試圖在我的表格中插入一些行'Quiz'。當我的表是空的,我嘗試插入它工作的第一行,但每當我試圖進入第二行我不斷收到此錯誤:在c中插入行時違反UNIQUE KEY約束條件#
Violation of UNIQUE KEY constraint 'UQ__Quiz__D0C4726C5B2346B6'. Cannot insert duplicate key in object 'dbo.Quiz'. The duplicate key value is (<NULL>).
我真的有一個想法什麼導致它,因爲我總是爲每一行輸入不同的ID。
表示層:
if (IsValidData())
{
quiz.QuizID = Convert.ToInt32(quizIDTextBox.Text);
quiz.QuizNaam = quizNaamTextBox.Text;
quiz.QuizDatum = Convert.ToString(quizDatumDateTimePicker.Text);
quiz.Locatie = locatieTextBox.Text;
quiz.Type = typeTextBox.Text;
quiz.Moeilijkheidsgraad = moeilijkheidsgraadTextBox.Text;
QuizDB.InsertQuiz(quiz);
MessageBox.Show("Quiz Toegevoegd", "Quiz");
}
數據庫層:
public static void InsertQuiz(Quiz quiz)
{
string insertStatement = "INSERT INTO Quiz (QuizID,QuizNaam,QuizDatum,Locatie,Type,Moeilijkheidsgraad) VALUES (@QuizID,@QuizNaam, @QuizDatum, @Locatie, @Type, @Moeilijkheidsgraad)";
SqlCommand quizCommand = new SqlCommand(insertStatement, conn);
quizCommand.Parameters.Clear();
quizCommand.Parameters.AddWithValue("@QuizID", quiz.QuizID);
quizCommand.Parameters.AddWithValue("@QuizNaam", quiz.QuizNaam);
quizCommand.Parameters.AddWithValue("@QuizDatum", quiz.QuizDatum);
quizCommand.Parameters.AddWithValue("@Locatie", quiz.Locatie);
quizCommand.Parameters.AddWithValue("@Type", quiz.Type);
quizCommand.Parameters.AddWithValue("@Moeilijkheidsgraad",quiz.Moeilijkheidsgraad);
try
{
conn.Open();
quizCommand.ExecuteNonQuery();
}
catch (SqlException ex)
{
throw ex;
}
finally
{
conn.Close();
}
}
經營業務層:
public class Quiz
{
private int cQuizId;
private string cQuizNaam;
private string cQuizDatum;
private int cWinnaarId;
private string cLocatie;
private string cType;
private string cMoeilijkheidsgraad;
public Quiz() { }
public int QuizID
{
get { return cQuizId;}
set { cQuizId = value; }
}
public string QuizNaam
{
get { return cQuizNaam; }
set { cQuizNaam = value; }
}
public string QuizDatum
{
get { return cQuizDatum; }
set { cQuizDatum = value; }
}
public int WinnaarId
{
get { return cWinnaarId; }
set { cWinnaarId = value; }
}
public string Locatie
{
get { return cLocatie; }
set { cLocatie = value; }
}
public string Type
{
get { return cType; }
set { cType = value; }
}
public string Moeilijkheidsgraad
{
get { return cMoeilijkheidsgraad; }
set { cMoeilijkheidsgraad = value; }
}
}
錯誤消息告訴你,你在'Quiz'表上有唯一性約束。你有沒有嘗試過將相同的值手動插入到表中? – 2013-02-11 13:34:59
您插入的第一個ID是否正確?它是一個整數嗎? – CristisS 2013-02-11 13:35:43
您是否在第一次插入後檢查了列值是否爲NULL?也許它帶給你一些提示,以找到問題... – HuorSwords 2013-02-11 13:35:45