diff --git a/Assets/Output/DBEvolution.cs b/Assets/Output/DBEvolution.cs
index 8a45ba8..2e9d23d 100644
--- a/Assets/Output/DBEvolution.cs
+++ b/Assets/Output/DBEvolution.cs
@@ -4,175 +4,197 @@
 
 namespace UnityORM
 {
-	/// <summary>
-	/// Schme management tool.
-	/// Execute only diff sqls.
-	/// </summary>
-	public class DBEvolution
-	{
-		
-		string dbFilePath;
-		SqliteDatabase database;
-		
-		public SqliteDatabase Database{
-			get{
-				if(database == null){
-					database = new SqliteDatabase();
-					
-					database.Open(dbFilePath);
-					CreateMetaTable();
-				}
-				return database;
-			}
-		}
-		
-		public bool RecreateTableIfHashDiffers{get;set;}
-		
-		/// <summary>
-		/// Initializes a new instance of the <see cref="com.geishatokyo.DB.DBEvolution"/> class.
-		/// </summary>
-		/// <param name='dbFilePath'>
-		/// Db file path.
-		/// </param>
-		public DBEvolution (string dbFilePath)
-		{
-			this.dbFilePath = dbFilePath;
-			RecreateTableIfHashDiffers = false;
-		}
-		
-		
-		/// <summary>
-		/// Evolute the specified tableName with sqls.
-		/// </summary>
-		/// <param name='tableName'>
-		/// Table name.
-		/// </param>
-		/// <param name='sqls'>
-		/// Sqls.
-		/// </param>
-		public void Evolute(string tableName, List<string> sqls){
-			TableVersion version = GetTableVersion(tableName);
-			var db = this.Database;
-			if(RecreateTableIfHashDiffers && version.QueryHash != null){
-				string hash;
-				if(sqls.Count > version.QueryIndex){
-					hash = GetHash(sqls.GetRange(0,version.QueryIndex + 1));
-				}else{
-					hash = "";
-				}
-				if(hash != version.QueryHash){
-					Debug.Log(string.Format("Table hash error.OnDB:{0} Passed:{1}",version.QueryHash,hash));
-					DropTable(tableName);
-					version.QueryIndex = -1;
-					version.QueryHash = null;
-				}
-			}
-			
-			bool updated = false;
-			int successIndex = -1;
-			bool error = false;
-			for(int i = version.QueryIndex + 1;i < sqls.Count;i++){
-				Debug.Log(string.Format("Execute query of {0}:{1}" ,tableName,i));
-				updated = true;
-				try{
-					db.ExecuteNonQuery(sqls[i]);
-					successIndex = i;
-				}catch(SqliteException e){
-					error = true;
-					Debug.Log("Error SQL:" + sqls[i]);
-					Debug.LogException(e);
-					break;
-				}
-			}
-			
-			if(successIndex >= 0){
-				sqls = sqls.GetRange(0,successIndex + 1);
-				if(version.QueryHash == null){
-					string hashCode = GetHash(sqls);
-					CreateRecord(tableName,sqls.Count - 1,hashCode);
-				}else{
-					string hashCode = GetHash(sqls);
-					UpdateRecord(tableName,sqls.Count - 1,hashCode);
-				}
-			}
-			
-			if(error){
-				Debug.Log("There are some errors.Please fix your sql");
-			}
-			
-		}
-		
-		public void Close(){
-			if(database != null){
-				database.Close();
-				database = null;
-			}
-		}
-		
-		string GetHash(List<string> sqls){
-			string join = string.Join("_",sqls.ToArray());
-			return join.GetHashCode().ToString();
-		}
-		
-		void CreateRecord(string tableName,int index,string queryHash){
-			string sql = string.Format(
-				@"INSERT INTO MetaTable VALUES('{0}',{1},'{2}');",tableName,index,queryHash);
-			Database.ExecuteNonQuery(sql);
-		}
-		void UpdateRecord(string tableName,int index,string queryHash){
-			string sql = string.Format(
-				@"UPDATE MetaTable SET queryIndex={0},queryHash='{1}' WHERE tableName='{2}';",
-				index,queryHash,tableName);
-			Database.ExecuteNonQuery(sql);
-		}
-		
-		void DropTable(string tableName){
-			Debug.Log("DROP TABLE IF EXISTS " + tableName);
-			string sql = string.Format(@"DROP TABLE IF EXISTS {0};",tableName);
-			Database.ExecuteNonQuery(sql);
-			
-			string metaSql = string.Format(@"DELETE FROM MetaTable WHERE tableName='{0}';",tableName);
-			Database.ExecuteNonQuery(metaSql);
-		}
-		
-		TableVersion GetTableVersion(string tableName){
-			string sql = @"SELECT * FROM MetaTable WHERE tableName = '" + tableName + "';";
-			DataTable dt = Database.ExecuteQuery(sql);
-			
-			TableVersion tv = new TableVersion();
-			if(dt.Rows.Count > 0){
-				tv.TableName = tableName;
-				var row = dt.Rows[0];
-				tv.QueryIndex = row.GetAsInt("queryIndex");
-				tv.QueryHash = row["queryHash"].ToString();
-			}else{
-				tv.TableName = tableName;
-				tv.QueryIndex = -1;
-				tv.QueryHash = null;
-			}
-			return tv;
-		}
-		
-		
-		
-		bool CreateMetaTable(){
-			string createTable = @"CREATE TABLE IF NOT EXISTS MetaTable(
+    /// <summary>
+    /// Schme management tool.
+    /// Execute only diff sqls.
+    /// </summary>
+    public class DBEvolution
+    {
+        private string dbFilePath;
+        private SqliteDatabase database;
+
+        public SqliteDatabase Database {
+            get {
+                if (database == null)
+                {
+                    database = new SqliteDatabase ();
+                    
+                    database.Open (dbFilePath);
+                    CreateMetaTable ();
+                }
+                return database;
+            }
+        }
+
+        public bool RecreateTableIfHashDiffers{ get; set; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="com.geishatokyo.DB.DBEvolution"/> class.
+        /// </summary>
+        /// <param name='dbFilePath'>
+        /// Db file path.
+        /// </param>
+        public DBEvolution (string dbFilePath)
+        {
+            this.dbFilePath = dbFilePath;
+            RecreateTableIfHashDiffers = false;
+        }
+
+        /// <summary>
+        /// Evolute the specified tableName with sqls.
+        /// </summary>
+        /// <param name='tableName'>
+        /// Table name.
+        /// </param>
+        /// <param name='sqls'>
+        /// Sqls.
+        /// </param>
+        public void Evolute (string tableName, List<string> sqls)
+        {
+            TableVersion version = GetTableVersion (tableName);
+            var db = this.Database;
+            if (RecreateTableIfHashDiffers && version.QueryHash != null)
+            {
+                string hash;
+                if (sqls.Count > version.QueryIndex)
+                {
+                    hash = GetHash (sqls.GetRange (0, version.QueryIndex + 1));
+                }
+                else
+                {
+                    hash = string.Empty;
+                }
+                if (hash != version.QueryHash)
+                {
+                    Debug.Log (string.Format ("Table hash error.OnDB:{0} Passed:{1}", version.QueryHash, hash));
+                    DropTable (tableName);
+                    version.QueryIndex = -1;
+                    version.QueryHash = null;
+                }
+            }
+
+            // TODO: use updated?
+            //bool updated = false;
+            int successIndex = -1;
+            bool error = false;
+
+            for (int i = version.QueryIndex + 1; i < sqls.Count; i++)
+            {
+                Debug.Log (string.Format ("Execute query of {0}:{1}", tableName, i));
+                //updated = true;
+                try
+                {
+                    db.ExecuteNonQuery (sqls [i]);
+                    successIndex = i;
+                }
+                catch (SqliteException e)
+                {
+                    error = true;
+                    Debug.LogError ("Error SQL:" + sqls [i]);
+                    Debug.LogException (e);
+                    break;
+                }
+            }
+
+            if (successIndex >= 0)
+            {
+                sqls = sqls.GetRange (0, successIndex + 1);
+                if (version.QueryHash == null)
+                {
+                    string hashCode = GetHash (sqls);
+                    CreateRecord (tableName, sqls.Count - 1, hashCode);
+                }
+                else
+                {
+                    string hashCode = GetHash (sqls);
+                    UpdateRecord (tableName, sqls.Count - 1, hashCode);
+                }
+            }
+
+            if (error)
+            {
+                Debug.LogError ("There are some errors.Please fix your sql");
+            }
+        }
+
+        public void Close ()
+        {
+            if (database != null)
+            {
+                database.Close ();
+                database = null;
+            }
+        }
+
+        private string GetHash (List<string> sqls)
+        {
+            string join = string.Join ("_", sqls.ToArray ());
+            return join.GetHashCode ().ToString ();
+        }
+
+        void CreateRecord (string tableName, int index, string queryHash)
+        {
+            string sql = string.Format (
+                @"INSERT INTO MetaTable VALUES('{0}',{1},'{2}');", tableName, index, queryHash);
+            Database.ExecuteNonQuery (sql);
+        }
+
+        void UpdateRecord (string tableName, int index, string queryHash)
+        {
+            string sql = string.Format (
+                @"UPDATE MetaTable SET queryIndex={0},queryHash='{1}' WHERE tableName='{2}';",
+                index, queryHash, tableName);
+            Database.ExecuteNonQuery (sql);
+        }
+
+        private void DropTable (string tableName)
+        {
+            Debug.Log ("DROP TABLE IF EXISTS " + tableName);
+            string sql = string.Format (@"DROP TABLE IF EXISTS {0};", tableName);
+            Database.ExecuteNonQuery (sql);
+
+            string metaSql = string.Format (@"DELETE FROM MetaTable WHERE tableName='{0}';", tableName);
+            Database.ExecuteNonQuery (metaSql);
+        }
+
+        private TableVersion GetTableVersion (string tableName)
+        {
+            string sql = @"SELECT * FROM MetaTable WHERE tableName = '" + tableName + "';";
+            DataTable dt = Database.ExecuteQuery (sql);
+            
+            TableVersion tv = new TableVersion ();
+            if (dt.Rows.Count > 0)
+            {
+                tv.TableName = tableName;
+                var row = dt.Rows [0];
+                tv.QueryIndex = row.GetAsInt ("queryIndex");
+                tv.QueryHash = row ["queryHash"].ToString ();
+            }
+            else
+            {
+                tv.TableName = tableName;
+                tv.QueryIndex = -1;
+                tv.QueryHash = null;
+            }
+            return tv;
+        }
+
+        private bool CreateMetaTable ()
+        {
+            string createTable = @"CREATE TABLE IF NOT EXISTS MetaTable(
 tableName VARCHAR(100) NOT NULL,
 queryIndex Int NOT NULL,
 queryHash VARCHAR(100) NOT NULL);";
-			Database.ExecuteNonQuery(createTable);
-			// TODO fix to check table is really created.
-			return true;
-		}
-		
-		
-		
-	}
-	
-	struct TableVersion{
-		public string TableName;
-		public int QueryIndex;
-		public string QueryHash;
-	}
-}
+            Database.ExecuteNonQuery (createTable);
+            // TODO fix to check table is really created.
+            return true;
+        }
+    }
 
+    struct TableVersion
+    {
+        public string TableName;
+        public int QueryIndex;
+        public string QueryHash;
+    }
+}