diff --git a/src/main/java/com/web/controller/BoardController.java b/src/main/java/com/web/controller/BoardController.java
index 048e41b..321b0f2 100644
--- a/src/main/java/com/web/controller/BoardController.java
+++ b/src/main/java/com/web/controller/BoardController.java
@@ -26,7 +26,7 @@ public BoardController(BoardService boardService) {
 
     @GetMapping({"", "/"})
     public String board(@RequestParam(value = "idx", defaultValue = "0") Long idx, Model model) {
-        model.addAttribute("board", boardService.findBoardByIdx(idx));
+        model.addAttribute("board", boardService.findBoardByIdx(idx).orElse(null));
         return "/board/form";
     }
 
diff --git a/src/main/java/com/web/domain/Board.java b/src/main/java/com/web/domain/Board.java
index f5078b1..ff9f08c 100644
--- a/src/main/java/com/web/domain/Board.java
+++ b/src/main/java/com/web/domain/Board.java
@@ -5,15 +5,7 @@
 import java.io.Serializable;
 import java.time.LocalDateTime;
 
-import javax.persistence.Column;
-import javax.persistence.Entity;
-import javax.persistence.EnumType;
-import javax.persistence.Enumerated;
-import javax.persistence.FetchType;
-import javax.persistence.GeneratedValue;
-import javax.persistence.Id;
-import javax.persistence.OneToOne;
-import javax.persistence.Table;
+import javax.persistence.*;
 
 import lombok.Builder;
 import lombok.Getter;
@@ -30,7 +22,7 @@ public class Board implements Serializable {
 
     @Id
     @Column
-    @GeneratedValue
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long idx;
 
     @Column
diff --git a/src/main/java/com/web/domain/User.java b/src/main/java/com/web/domain/User.java
index f302e83..d665d3f 100644
--- a/src/main/java/com/web/domain/User.java
+++ b/src/main/java/com/web/domain/User.java
@@ -3,11 +3,7 @@
 import java.io.Serializable;
 import java.time.LocalDateTime;
 
-import javax.persistence.Column;
-import javax.persistence.Entity;
-import javax.persistence.GeneratedValue;
-import javax.persistence.Id;
-import javax.persistence.Table;
+import javax.persistence.*;
 
 import lombok.Builder;
 import lombok.Getter;
@@ -24,7 +20,7 @@ public class User implements Serializable {
 
     @Id
     @Column
-    @GeneratedValue
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long idx;
 
     @Column
diff --git a/src/main/java/com/web/service/BoardService.java b/src/main/java/com/web/service/BoardService.java
index 3dbc193..c382737 100644
--- a/src/main/java/com/web/service/BoardService.java
+++ b/src/main/java/com/web/service/BoardService.java
@@ -7,6 +7,8 @@
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 
+import java.util.Optional;
+
 /**
  * Created by KimYJ on 2017-07-13.
  */
@@ -24,8 +26,8 @@ public Page<Board> findBoardList(Pageable pageable) {
         return boardRepository.findAll(pageable);
     }
 
-    public Board findBoardByIdx(Long idx) {
-        return boardRepository.getOne(idx);
+    public Optional<Board> findBoardByIdx(Long idx) {
+        return boardRepository.findById(idx);
     }
 
     public Board saveAndUpdateBoard(Board board) {