Merge pull request #51 from msallin/Issue-48

Fix for #48 and documentation (#25).

Author: msallin

SQLite.CodeFirst/SqliteCreateDatabaseIfNotExists.cs

@@ -3,18 +3,59 @@
 
 namespace SQLite.CodeFirst
 {
+    /// <summary>
+    /// An implementation of <see cref="IDatabaseInitializer{TContext}"/> that will recreate and optionally re-seed the
+    /// database only if the database does not exist. To seed the database, create a derived class and override the Seed method. 
+    /// </summary>
+    /// <typeparam name="TContext">The type of the context.</typeparam>
     public class SqliteCreateDatabaseIfNotExists<TContext> : SqliteInitializerBase<TContext>
         where TContext : DbContext
     {
+        private readonly bool nullByteFileMeansNotExisting;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SqliteCreateDatabaseIfNotExists{TContext}"/> class.
+        /// </summary>
+        /// <param name="modelBuilder">The model builder.</param>
         public SqliteCreateDatabaseIfNotExists(DbModelBuilder modelBuilder)
-            : base(modelBuilder) { }
+            : this(modelBuilder, false)
+        { }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SqliteCreateDatabaseIfNotExists{TContext}"/> class.
+        /// </summary>
+        /// <param name="modelBuilder">The model builder.</param>
+        /// <param name="nullByteFileMeansNotExisting">if set to <c>true</c> a null byte database file is treated like the database does not exist.</param>
+        public SqliteCreateDatabaseIfNotExists(DbModelBuilder modelBuilder, bool nullByteFileMeansNotExisting)
+            : base(modelBuilder)
+        {
+            this.nullByteFileMeansNotExisting = nullByteFileMeansNotExisting;
+        }
+
+        /// <summary>
+        /// Initialize the database for the given context.
+        /// Generates the SQLite-DDL from the model and executs it against the database.
+        /// After that the <see cref="Seed" /> method is executed.
+        /// All actions are be executed in transactions.
+        /// </summary>
+        /// <param name="context">The context.</param>
         public override void InitializeDatabase(TContext context)
         {
-            string databseFilePath = GetDatabasePathFromContext(context);
+            string databaseFilePath = GetDatabasePathFromContext(context);
+
+            var fileInfo = new FileInfo(databaseFilePath);
+
+            bool exists;
+            if (nullByteFileMeansNotExisting)
+            {
+                exists = fileInfo.Exists && fileInfo.Length != 0;
+            }
+            else
+            {
+                exists = fileInfo.Exists;
+            }
 
-            bool dbExists = File.Exists(databseFilePath);
-            if (dbExists)
+            if (exists)
             {
                 return;
             }

SQLite.CodeFirst/SqliteDatabaseCreator.cs

@@ -5,6 +5,10 @@
 
 namespace SQLite.CodeFirst
 {
+    /// <summary>
+    /// Creates a SQLite-Database based on a Entity Framework <see cref="Database"/> and <see cref="DbModel"/>.
+    /// This creator can be used standalone or within an initializer.
+    /// </summary>
     public class SqliteDatabaseCreator
     {
         private readonly Database db;
@@ -16,6 +20,9 @@ public SqliteDatabaseCreator(Database db, DbModel model)
             this.model = model;
         }
 
+        /// <summary>
+        /// Creates the SQLite-Database.
+        /// </summary>
         public void Create()
         {
             IStatementBuilder<CreateDatabaseStatement> statementBuilder = new CreateDatabaseStatementBuilder(model.StoreModel);

SQLite.CodeFirst/SqliteDropCreateDatabaseAlways.cs

@@ -3,12 +3,29 @@
 
 namespace SQLite.CodeFirst
 {
+    /// <summary>
+    /// An implementation of <see cref="IDatabaseInitializer{TContext}"/> that will always recreate and optionally re-seed the 
+    /// database the first time that a context is used in the app domain. To seed the database, create a derived class and override the Seed method.
+    /// </summary>
+    /// <typeparam name="TContext">The type of the context.</typeparam>
     public class SqliteDropCreateDatabaseAlways<TContext> : SqliteInitializerBase<TContext>
         where TContext : DbContext
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SqliteDropCreateDatabaseAlways{TContext}"/> class.
+        /// </summary>
+        /// <param name="modelBuilder">The model builder.</param>
         public SqliteDropCreateDatabaseAlways(DbModelBuilder modelBuilder)
-            : base(modelBuilder) { }
+            : base(modelBuilder)
+        { }
 
+        /// <summary>
+        /// Initialize the database for the given context.
+        /// Generates the SQLite-DDL from the model and executs it against the database.
+        /// After that the <see cref="Seed" /> method is executed.
+        /// All actions are be executed in transactions.
+        /// </summary>
+        /// <param name="context">The context.</param>
         public override void InitializeDatabase(TContext context)
         {
             string databseFilePath = GetDatabasePathFromContext(context);