diff --git a/HSUCO_Cargo_Garage_Operation_Program/Database.cs b/HSUCO_Cargo_Garage_Operation_Program/Database.cs
index b8d8181..4be240a 100644
--- a/HSUCO_Cargo_Garage_Operation_Program/Database.cs
+++ b/HSUCO_Cargo_Garage_Operation_Program/Database.cs
@@ -15,11 +15,17 @@ namespace HSUCO_Cargo_Garage_Operation_Program
         private static readonly string CONNECTION_STRING =
             $"Data Source={DBLocation}; Version=3; Integrated Security=true;";
 
+        /// <summary>
+        /// 최초 호출시 Database 연결
+        /// </summary>
         static Database()
         {
             CreateDatabaseIfNotExist();
         }
 
+        /// <summary>
+        /// Database 연결시 파일이 없으면 Database Table 생성
+        /// </summary>
         private static void CreateDatabaseIfNotExist()
         {
             if (!File.Exists(DBLocation))
@@ -157,7 +163,10 @@ namespace HSUCO_Cargo_Garage_Operation_Program
                 OpenConnection();
             }
         }
-
+        /// <summary>
+        /// Dtabase 연결
+        /// </summary>
+        /// <returns>SQLiteConnection 정보</returns>
         private static SQLiteConnection OpenConnection()
         {
             _sqLiteConnection = new SQLiteConnection(CONNECTION_STRING);
@@ -167,14 +176,14 @@ namespace HSUCO_Cargo_Garage_Operation_Program
         }
 
         /// <summary>
-        ///     신청자 리스트에서 화물차 번호로 중복자 조회
+        /// 차량번호로 이미 신청한 차량인지 조회
         /// </summary>
         /// <param name="CargoVehicleNumber">화물차 번호</param>
-        /// <returns></returns>
+        /// <returns>중복 여부</returns>
         public static bool ApplicantCheckAlready(string CargoVehicleNumber)
         {
             var count = 0;
-            var query = string.Format($"SELECT COUNT(*) From ViewApplicantList Where CargoVehicleNumber = '{0}' And RegistrationStatus={(int)ERegistrationStatus.Wait};",
+            var query = string.Format($"SELECT COUNT(*) FROM ViewApplicantList WHERE CargoVehicleNumber = '{0}' AND RegistrationStatus={(int)ERegistrationStatus.Wait};",
                 CargoVehicleNumber.Trim());
 
             using (var command = _sqLiteConnection.CreateCommand())
@@ -191,11 +200,16 @@ namespace HSUCO_Cargo_Garage_Operation_Program
             return count > 0;
         }
 
+        /// <summary>
+        /// 사용자 리스트에서 사용자 찾기
+        /// </summary>
+        /// <param name="CargoVehicleNumber">화물차 번호</param>
+        /// <returns>중복 여부</returns>
         public static bool UserListCheckAlready(string CargoVehicleNumber)
         {
             var count = 0;
-            var query = "SELECT COUNT(*) From ViewUserList WHERE DateEnd >= \"" + DateTime.Now +
-                        "\" And CargoVehicleNumber = \"" + CargoVehicleNumber + "\"";
+            var query = "SELECT COUNT(*) FROM ViewUserList WHERE DateEnd >= \"" + DateTime.Now +
+                        "\" AND CargoVehicleNumber = \"" + CargoVehicleNumber + "\"";
 
             using (var command = _sqLiteConnection.CreateCommand())
             {