Added migrations

DbTools.csproj

@@ -42,8 +42,12 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Delta.cs" />
+    <Compile Include="EventArguments\MigrationCompletedEventArgs.cs" />
+    <Compile Include="EventArguments\MigrationProgressEventArgs.cs" />
+    <Compile Include="EventArguments\MigrationStartedEventArgs.cs" />
     <Compile Include="Extensions\DatabaseExtensions.cs" />
     <Compile Include="Extensions\TableExtensions.cs" />
+    <Compile Include="Migrations.cs" />
     <Compile Include="Model\Column.cs" />
     <Compile Include="Model\ColumnCollection.cs" />
     <Compile Include="Model\Database.cs" />

EventArguments/MigrationCompletedEventArgs.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace DbTools.EventArguments {
+    public delegate void MigrationCompletedEventHandler(object sender, MigrationCompletedEventArgs e);
+
+    public class MigrationCompletedEventArgs : EventArgs {
+        public string MigrationName { get; set; }
+        public bool WasSuccessful { get; set; }
+        public Exception Error { get; set; }
+        public int Remaining { get; set; }
+
+        public MigrationCompletedEventArgs() { }
+        public MigrationCompletedEventArgs(string migrationName, int remaining, Exception error = null, bool wasSuccessful = true) {
+            MigrationName = migrationName;
+            WasSuccessful = error != null ? false : wasSuccessful;
+            Error = error;
+            Remaining = remaining;
+        }
+    }
+}

EventArguments/MigrationProgressEventArgs.cs

@@ -0,0 +1,23 @@
+using System;
+
+namespace DbTools.EventArguments {
+    public delegate void MigrationProgressEventHandler(object sender, MigrationProgressEventArgs e);
+
+    public class MigrationProgressEventArgs : EventArgs {
+        public string StatusText { get; set; }
+        public int Total { get; set; }
+        public int Pending { get; set; }
+        public int Successful { get; set; }
+        public int Failed { get; set; }
+
+        public MigrationProgressEventArgs() { }
+
+        public MigrationProgressEventArgs(int total, int pending, int successful, int failed, string statusText = "") {
+            Total = total;
+            Pending = pending;
+            Successful = successful;
+            Failed = failed;
+            StatusText = statusText;
+        }
+    }
+}

EventArguments/MigrationStartedEventArgs.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace DbTools.EventArguments {
+    public delegate void MigrationStartedEventHandler(object sender, MigrationStartedEventArgs e);
+
+    public class MigrationStartedEventArgs : EventArgs {
+        public string MigrationName { get; set; }
+        public int Remaining { get; set; }
+
+        public MigrationStartedEventArgs() { }
+        public MigrationStartedEventArgs(string migrationName, int remaining) {
+            MigrationName = migrationName;
+            Remaining = remaining;
+        }
+    }
+}

Migrations.cs

@@ -0,0 +1,107 @@
+using DbTools.EventArguments;
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace DbTools {
+    public class Migrations {
+        public string MigrationPath { get; set; }
+        public string CompletedMigrationFile { get; set; } = "migrations.txt";
+
+        public int Pending { get; private set; }
+        public int Successful { get; private set; }
+        public int Failed { get; private set; }
+        public int Total { get; private set; }
+
+        public event MigrationProgressEventHandler MigrationProgressReported;
+        public event MigrationCompletedEventHandler MigrationCompleted;
+        public event MigrationStartedEventHandler MigrationStarted;
+
+        public Migrations(string migrationPath) {
+            MigrationPath = migrationPath;
+            if (!Directory.Exists(MigrationPath)) {
+                Directory.CreateDirectory(MigrationPath);
+            }
+        }
+
+        public string[] GetAvailableMigrations(string databaseName, bool includeFailed = false) {
+            string completedFile = Path.Combine(MigrationPath, CompletedMigrationFile);
+            List<string> completedMigrations = new List<string>();
+            if (!File.Exists(completedFile)) {
+                File.WriteAllText(completedFile, "");
+            }
+
+            // migrations.txt format: filename.sql;date_time_performed;success=1-or-fail=0
+            //                        data_6.0.12.123_01.sql;25252511;1
+            string[] migrations = File.ReadAllLines(completedFile);
+            foreach (string migration in migrations) {
+                string[] parts = migration.Split(';');
+                if (int.Parse(parts[2] ?? "0") != 0) {
+                    completedMigrations.Add(migration);
+                }
+            }
+
+            var migrationFiles = Directory.GetFiles(MigrationPath, databaseName + "_*.sql")
+                .Where(f => !completedMigrations.Contains(Path.GetFileName(f)))
+                .OrderBy(f => f);
+
+            return migrationFiles.ToArray();
+        }
+
+        public void MarkMigrationComplete(string migrationName, bool wasSuccessful = true) {
+            File.AppendAllText(Path.Combine(MigrationPath, CompletedMigrationFile),
+                migrationName + ";" + DateTime.Now.ToString("yyyyMMddHHmmss") + ";" + Convert.ToInt16(wasSuccessful).ToString() + Environment.NewLine);
+        }
+
+        public async Task ApplyMigrationsAsync(IDbConnection dbConnection, string databaseName, bool attemptFailed = false) {
+            await Task.Run(() => {
+                ApplyMigrations(dbConnection, databaseName, attemptFailed);
+            });
+        }
+
+        public void ApplyMigrations(IDbConnection dbConnection, string databaseName, bool attemptFailed = false) {
+            string[] migrationFiles = GetAvailableMigrations(databaseName, attemptFailed);
+            Total = migrationFiles.Count();
+            Pending = Total;
+            Failed = 0;
+            Successful = 0;
+
+            // Iterate through the migrations reporting progress along the way
+            foreach (var migration in migrationFiles) {
+                string migrationName = Path.GetFileNameWithoutExtension(migration);
+                MigrationStarted?.Invoke(this, new MigrationStartedEventArgs(migrationName, --Pending));
+                MigrationProgressReported?.Invoke(this, new MigrationProgressEventArgs(Total, Pending, Successful, Failed, $"Started Migration '{migrationName}'..."));
+
+                // TODO : Do the work
+                Exception error = null;
+                bool wasSuccessful = false;
+                try {
+                    using (var cmd = dbConnection.CreateCommand()) {
+                        cmd.CommandText = File.ReadAllText(migration);
+                        if (cmd.ExecuteNonQuery() > 0) {
+                            wasSuccessful = true;
+                        }
+                        wasSuccessful = false;
+                    }
+                } catch (Exception ex) {
+                    error = ex;
+                    wasSuccessful = false;
+                }
+
+                // Report progress
+                if (wasSuccessful) {
+                    Successful++;
+                } else {
+                    Failed++;
+                }
+                MigrationCompleted?.Invoke(this, new MigrationCompletedEventArgs(migrationName, Pending, error, wasSuccessful));
+                MigrationProgressReported?.Invoke(this, new MigrationProgressEventArgs(Total, Pending, Successful, Failed,
+                    (wasSuccessful ? "Successfully" : "Unsuccessfully") + $" Completed Migration '{migrationName}'."));
+                MarkMigrationComplete(migrationName + ".sql", wasSuccessful);
+            }
+        }
+    }
+}