Initial commit

2026-07-12 16:06:18 +04:00
commit 1d16eeacb2
23 changed files with 2298 additions and 0 deletions
@@ -0,0 +1,127 @@
+using System;
+using System.Windows.Forms;
+using System.Data;
+using System.Data.OleDb;
+using System.Text;
+
+namespace Database {
+    static public class OleDBHandler {
+        static private OleDbConnection connection;
+        static public OleDbConnection Connection {
+            get {
+                if (connection == null) {
+                    InitializeConnection();
+                }
+                return connection;
+            }
+        }
+        static private void InitializeConnection() {
+            try {
+                using (var ofDlg = new OpenFileDialog()) {
+                    ofDlg.InitialDirectory = "c:\\";
+                    ofDlg.Filter = "Access database files (*.accdb;*.mdb)|*.accdb;*.mdb";
+                    ofDlg.RestoreDirectory = true;
+                    ofDlg.CheckFileExists = true;
+
+                    if (ofDlg.ShowDialog() == DialogResult.OK) {
+                        connection = new OleDbConnection(string.Format(
+                            "Provider = Microsoft.ACE.Oledb.12.0; Data Source = {0}"
+                            , ofDlg.FileName
+                        ));
+                    }
+                    else {
+                        Environment.Exit(0);
+                    }
+                }
+                connection.Open();
+            }
+            catch (Exception e) {
+                MessageBox.Show(
+                    e.Message
+                    , "Database connection error"
+                    , MessageBoxButtons.OK
+                    , MessageBoxIcon.Error
+                );
+                Environment.Exit(e.HResult);
+            }
+        }
+        public enum ExecuteType { NonQuery, Scalar };
+        public static object Execute(string command, ExecuteType type)
+        {
+            using (var statement = new OleDbCommand(command, Connection))
+            {
+                switch (type)
+                {
+                    case ExecuteType.NonQuery:
+                        return statement.ExecuteNonQuery();
+                    case ExecuteType.Scalar:
+                        return statement.ExecuteScalar();
+                    default:
+                        throw new ArgumentException("An unsupported method is specified");
+                }
+            }
+        }
+        public static OleDbCommand SelectCommand(string tableName, string fields)
+        {
+            var command = $"SELECT {fields} FROM [{tableName}];";
+            return new OleDbCommand(command, Connection);
+        }
+        public static bool Delete(string tableName, int id) {
+            string command = $"DELETE FROM [{tableName}] WHERE [id] = {id};";
+            var result = Execute(command, ExecuteType.NonQuery);
+            return Convert.ToBoolean(result);
+        }
+        private static string UpdatePart(params (string, object)[] listPairColumnNameValue) {
+            StringBuilder result = new StringBuilder(string.Empty);
+            var size = listPairColumnNameValue.Length;
+            if (size < 1)
+                return result.ToString();
+            foreach (var pair in listPairColumnNameValue)
+                if(pair.Item2 is string)
+                  result.Append($"[{pair.Item1}]='{pair.Item2}',");
+                else
+                    result.Append($"[{pair.Item1}]={pair.Item2},");
+
+            return result.ToString().TrimEnd(',');
+        }
+        public static bool Update(string tableName, int id, params (string, object)[] listPairColumnNameValue)
+        {
+            string partCommand = UpdatePart(listPairColumnNameValue);
+            if (partCommand.Length < 1)
+                return true;
+            string command = $"UPDATE [{tableName}] SET {partCommand} WHERE [id] = {id};";
+            var result = Execute(command, ExecuteType.NonQuery);
+            return Convert.ToBoolean(result);
+        }
+        private static string InsertPart(params (string, object)[] listPairColumnNameValue)
+        {
+            var size = listPairColumnNameValue.Length;
+            if (size < 1)
+                return string.Empty;
+
+            StringBuilder left = new StringBuilder("(");
+            StringBuilder right = new StringBuilder("VALUES (");
+            foreach (var pair in listPairColumnNameValue) {
+                left.Append('[');
+                left.Append(pair.Item1);
+                left.Append("],");
+                if (pair.Item2 is string)
+                    right.Append('\'' + pair.Item2.ToString() + '\'' + ',');
+                else
+                    right.Append(pair.Item2.ToString() + ',');
+            }
+            var leftResult = left.ToString().TrimEnd(',') + ')';
+            var rightResult = right.ToString().TrimEnd(',') + ')';
+            return leftResult + rightResult;
+        }
+            public static bool Insert(string tableName, params (string, object)[] listPairColumnNameValue)
+        {
+            string partCommand = InsertPart(listPairColumnNameValue);
+            if (partCommand.Length < 1)
+                return true;
+            string command = $"INSERT INTO [{tableName}] {partCommand};";
+            var result = Execute(command, ExecuteType.NonQuery);
+            return Convert.ToBoolean(result);
+        }
+    }
+}