Question

我正在尝试在内存中创建数据库，但是当我尝试运行该应用程序时，我收到以下错误：

System.Data.SQLite.SQLiteException: 'constraint failed

UNIQUE constraint failed: spisakhyd.Station'

可以帮我解决错误和需要改变的地方吗？

我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SQLite;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        private SQLiteConnection Connection;

        public Form1()
        {
            InitializeComponent();

            label3.Hide();
            label4.Hide();

            SQLiteConnection.CreateFile("hydrodb.sqlite");
            SQLiteConnection Connection = new SQLiteConnection("Data Source=hydrodb.sqlite;Version=3;");
            Connection.Open();

            string createTable = ("CREATE TABLE hyddnev (Station UNSIGNED INT(5) NOT NULL PRIMARY KEY, Dat datetime NOT NULL, Stoej int(5) DEFAULT NULL, Vkol UNSIGNED FLOAT(7,3) DEFAULT NULL, CodH varchar(1) DEFAULT NULL, CodQ varchar(1) DEFAULT NULL, Temp float(3,1) DEFAULT NULL)");
            SQLiteCommand createHydDnev = new SQLiteCommand(createTable, Connection);
            createHydDnev.ExecuteNonQuery();

            string createTable2 = ("CREATE TABLE hydmes (Station UNSIGNED INT(5) NOT NULL PRIMARY KEY, Dat datetime NOT NULL, StoejMin smallint(5) DEFAULT NULL, VkolMin UNSIGNED FLOAT(7,3) DEFAULT NULL, StoejSre smallint(5) DEFAULT NULL, VkolSre UNSIGNED FLOAT(7,3) DEFAULT NULL, StoejMax smallint(5) DEFAULT NULL, VkolMax UNSIGNED FLOAT(7,3) DEFAULT NULL)");
            SQLiteCommand createHydMes = new SQLiteCommand(createTable2, Connection);
            createHydMes.ExecuteNonQuery();

            string createTable3 = ("CREATE TABLE spisakhyd (Station UNSIGNED INT(5) NOT NULL PRIMARY KEY, NasMesto varchar(50) DEFAULT NULL, ImeReka varchar(50) DEFAULT NULL, Lati varchar(7) DEFAULT NULL, Longi varchar(7) DEFAULT NULL, Alti float(6,2) DEFAULT NULL, Star varchar(10) DEFAULT NULL)");
            SQLiteCommand createSpisakHyd = new SQLiteCommand(createTable3, Connection);
            createSpisakHyd.ExecuteNonQuery();

            this.Connection = Connection;
        }

        string pathFolder;
        string pathFolder2;

        string resultStation;
        string resultStation2;

        List<string> resultYears = new List<string>();
        List<string> resultYears2 = new List<string>();

        private void button1_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog dialog = new OpenFileDialog())
            {
                if (dialog.ShowDialog(this) == DialogResult.OK)
                {
                    string sFileName = dialog.FileName;
                    pathFolder = sFileName;

                    label3.Text = pathFolder;
                    label3.Show();                 

                    string[] lines = System.IO.File.ReadAllLines(dialog.FileName);

                    int i = 0;

                    foreach (var line in lines)
                    {

                        var splittedValues = line.Split(',');

                        var firstWord = splittedValues[0];
                        var firstYear = splittedValues[1];

                        if (!resultYears.Contains(firstYear))
                        {
                            resultYears.Add(firstYear);
                        }


                        if (i == 0)
                        {
                            resultStation = firstWord;
                        }
                        else
                        {
                            if (resultStation != firstWord)
                            {
                                MessageBox.Show("Файла с дневни данни трябва да съдържа само една станция!");
                                return;
                            }
                        }

                        i++;

                        string insertStation = ("insert into spisakhyd(Station) values(" + resultStation + ")");

                        SQLiteCommand insertSpisakHyd = new SQLiteCommand(insertStation, Connection);
                        insertSpisakHyd.ExecuteNonQuery();

                    }
                    resultYears.Sort();
                }
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog dialog = new OpenFileDialog())
            {
                if (dialog.ShowDialog(this) == DialogResult.OK)
                {
                    string sFileName = dialog.FileName;
                    pathFolder2 = sFileName;

                    label4.Text = pathFolder2;
                    label4.Show();

                    string[] lines = System.IO.File.ReadAllLines(dialog.FileName);

                    int i = 0;

                    foreach (var line in lines)
                    {
                        var splittedValues = line.Split(',');

                        var firstWord = splittedValues[0];
                        var firstYear2 = splittedValues[1];

                        if (!resultYears2.Contains(firstYear2))
                        {
                            resultYears2.Add(firstYear2);
                        }

                        if (i == 0)
                        {
                            resultStation2 = firstWord;
                        }
                        else
                        {
                            if (resultStation2 != firstWord)
                            {
                                MessageBox.Show("Файла с месечни данни трябва съдържа само една станция!");
                                return;
                            }
                        }

                        i++;
                    }

                    resultYears2.Sort();
                }
            }
        }

        public void label3_Click(object sender, EventArgs e)
        {

        }

        public void label4_Click(object sender, EventArgs e)
        {

        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (resultStation != resultStation2)
            {
                MessageBox.Show("Номера на станцията в единия файл не отговаря на номера на станцията в другият файл!" + Environment.NewLine + Environment.NewLine +
                    "ЗАБЕЛЕЖКА!" + Environment.NewLine + Environment.NewLine + "В двата файла, номера на станцията трябва да бъде един и същ!");
            }

            comboBox1.Items.Add(resultStation);

            if (string.Join(", ", resultYears) == string.Join(", ", resultYears2))
            //if (resultYears.Equals(resultYears2))
            {
                for (int i = 0; i < this.resultYears.Count; i++)
                {
                    comboBox2.Items.Add(resultYears[i]);
                }
            }
            else
            {
                MessageBox.Show("Годините от двата файла не съвпадат.");
            }

        }
    }
}

调试器停在第102行.. 我不明白为什么当我创建数据库并建立密切关系并且只想使用下一个类调试器停在第102行？

Answer 1

如documentation所示，type-name只能在最后一个单词后面的括号中包含数字。也就是说，您必须将unsigned放在mediumint之前。

（请注意，SQLite使用dynamic typing，因此unsigned mediumint(5)与somewhat signed notoriously big int(-5)相同，或只是int。）

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