From 22d2978cd11155f006e61a4a2e3541d54ebbedfb Mon Sep 17 00:00:00 2001
From: hzd <2685273579@qq.com>
Date: Thu, 13 Mar 2025 12:36:34 +0800
Subject: [PATCH] Fix null pointer exception in Parser when a transaction
 commit or rollback.

---
 src/java/simpledb/Parser.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/java/simpledb/Parser.java b/src/java/simpledb/Parser.java
index 8608fd68..b879595b 100644
--- a/src/java/simpledb/Parser.java
+++ b/src/java/simpledb/Parser.java
@@ -432,20 +432,20 @@ public void handleTransactStatement(ZTransactStmt s)
                     throw new ParsingException(
                             "No transaction is currently running");
                 curtrans.commit();
-                curtrans = null;
                 inUserTrans = false;
                 System.out.println("Transaction " + curtrans.getId().getId()
                         + " committed.");
+                curtrans = null;
                 break;
             case "ROLLBACK":
                 if (curtrans == null)
                     throw new ParsingException(
                             "No transaction is currently running");
                 curtrans.abort();
-                curtrans = null;
                 inUserTrans = false;
                 System.out.println("Transaction " + curtrans.getId().getId()
                         + " aborted.");
+                curtrans = null;
 
                 break;
             case "SET TRANSACTION":