EnsureDatabase and DropDatabase implemented

src/Sample/Program.cs

@@ -13,6 +13,12 @@ static int Main()
             var config = GetConfig();
             string connectionString = config.GetConnectionString("SampleFirebird");
 
+            // If you used `docker compose up` for creating a server and a database, the database already exists.
+            // You can see that a new database can be created using EnsureDatabase.For.FirebirdDatabase(connectionString) by changing the Database parameter (the fdb filename)
+            // in the connectionString in appsettings.json
+            // You can also try to drop a database by using DropDatabase.For.FirebirdDatabase(connectionString);
+            EnsureDatabase.For.FirebirdDatabase(connectionString);
+
             var upgrader =
                 DeployChanges.To
                     .FirebirdDatabase(connectionString)

src/dbup-firebird/FirebirdExtensions.cs

@@ -1,6 +1,11 @@
-using DbUp.Builder;
+using System;
+using System.IO;
+using DbUp;
+using DbUp.Builder;
+using DbUp.Engine.Output;
 using DbUp.Engine.Transactions;
 using DbUp.Firebird;
+using FirebirdSql.Data.FirebirdClient;
 
 // ReSharper disable once CheckNamespace
 
@@ -49,4 +54,124 @@ public static UpgradeEngineBuilder FirebirdDatabase(IConnectionManager connectio
         builder.WithPreprocessor(new FirebirdPreprocessor());
         return builder;
     }
-}
+
+
+    //The code below concerning EnsureDatabase and DropDatabase is a modified version from a PR from Github user @hhindriks. Thank you for your contribution.
+
+    //Error codes from Firebird (see https://www.firebirdsql.org/pdfrefdocs/Firebird-2.1-ErrorCodes.pdf)
+    const int FbIoError = 335544344;
+    const int FbNetworkError = 335544721;
+    const int FbLockTimeout = 335544510;
+
+    /// <summary>
+    /// Ensures that the database specified in the connection string exists.
+    /// </summary>
+    /// <param name="supported">Fluent helper type.</param>
+    /// <param name="connectionString">The connection string.</param>
+    /// <param name="logger">The <see cref="DbUp.Engine.Output.IUpgradeLog"/> used to record actions.</param>
+    /// <returns></returns>
+    public static void FirebirdDatabase(this SupportedDatabasesForEnsureDatabase supported, string connectionString, IUpgradeLog logger = null)
+    {
+        logger ??= new ConsoleUpgradeLog();
+        var builder = new FbConnectionStringBuilder(connectionString);
+
+        if (builder.ServerType == FbServerType.Embedded)
+        {
+            //The code for the embedded servertype is currently not tested.
+            //Comes from the original PR from @hhindriks
+            if (!File.Exists(builder.Database))
+            {
+                FbConnection.CreateDatabase(builder.ToString());
+                logger.WriteInformation("Created database {0}", builder.Database);
+            }
+            else
+            {
+                logger.WriteInformation("Database {0} already exists", builder.Database);
+            }
+        }
+        else
+        {
+            using var conn = new FbConnection(builder.ToString());
+            try
+            {
+                conn.Open();
+                conn.Close();
+                logger.WriteInformation("Database {0} already exists", builder.Database);
+            }
+            catch (FbException ex) when (ex.ErrorCode == FbIoError)
+            {
+                FbConnection.CreateDatabase(builder.ToString());
+                logger.WriteInformation("Created database {0}", builder.Database);
+            }
+            catch (FbException ex) when (ex.ErrorCode == FbNetworkError)
+            {
+                logger.WriteError("Could not access server. The server: {0} is probably not started.", builder.DataSource);
+                throw;
+            }
+            catch (FbException)
+            {
+                logger.WriteError("Ensure Database: Unknown firebird error when trying to access the server: {0}.", builder.DataSource);
+                throw;
+            }
+            catch (Exception)
+            {
+                logger.WriteError("Ensure Database: Unknown error when trying to access the server: {0}.", builder.DataSource);
+                throw;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Drop the database specified in the connection string.
+    /// </summary>
+    /// <param name="supported">Fluent helper type.</param>
+    /// <param name="connectionString">The connection string.</param>
+    /// <param name="logger">The <see cref="DbUp.Engine.Output.IUpgradeLog"/> used to record actions.</param>
+    /// <returns></returns>
+    public static void FirebirdDatabase(this SupportedDatabasesForDropDatabase supported, string connectionString, IUpgradeLog logger = null)
+    {
+        logger ??= new ConsoleUpgradeLog();
+        var builder = new FbConnectionStringBuilder(connectionString);
+
+        if (builder.ServerType == FbServerType.Embedded)
+        {
+            //The code for the embedded servertype is currently not tested.
+            //Comes from the original PR from @hhindriks
+            if (File.Exists(builder.Database))
+            {
+                FbConnection.DropDatabase(builder.ToString());
+                logger.WriteInformation("Dropped database {0}", builder.Database);
+            }
+        }
+        else
+        {
+            try
+            {
+                //There seems to be an error in the FirebirdClient when trying to drop a database that does not exist.
+                //It gives a NullRefException instead of the expected FbException.
+                FbConnection.DropDatabase(builder.ToString());
+                logger.WriteInformation("Dropped database {0}", builder.Database);
+            }
+            catch (FbException ex) when (ex.ErrorCode == FbIoError)
+            {
+                logger.WriteWarning("Nothing to Drop. No database found.");
+            }
+            catch (FbException ex) when (ex.ErrorCode == FbLockTimeout)
+            {
+                logger.WriteError("Can't drop database. Are there still an active connection?");
+                throw;
+            }
+            catch (FbException)
+            {
+                logger.WriteError("Drop Database: Unknown firebird error when trying to access the server: {0}.", builder.DataSource);
+                throw;
+            }
+            catch (Exception)
+            {
+                logger.WriteError("Drop Database: Unknown error when trying to access the server: {0}.", builder.DataSource);
+                throw;
+            }
+        }
+    }
+
+}