From c65e42907259d7b0d1f49a832ce3a39c9f697639 Mon Sep 17 00:00:00 2001
From: Syngnat <yangguofeng919@gmail.com>
Date: Thu, 30 Apr 2026 08:33:24 +0800
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B=20fix(oracle):=20=E5=85=BC?=
 =?UTF-8?q?=E5=AE=B9=E6=97=A7=E7=89=88=E6=9C=AC=E8=87=AA=E5=8A=A8=E9=99=90?=
 =?UTF-8?q?=E8=A1=8C=E8=AF=AD=E6=B3=95?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Oracle/Dameng 自动限行改为 ROWNUM 外层包裹
- 避免旧版本 Oracle 不支持 FETCH FIRST 导致 ORA-00933
- 保留尾部分号与注释，避免执行语句结构丢失
- 跳过 FOR UPDATE 语句自动包裹，避免改变锁语义
- 补充 Oracle/Dameng 自动限行回归测试
Refs #429
---
 frontend/src/utils/queryAutoLimit.test.ts | 20 +++++++++++++++-----
 frontend/src/utils/queryAutoLimit.ts      |  4 +++-
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/frontend/src/utils/queryAutoLimit.test.ts b/frontend/src/utils/queryAutoLimit.test.ts
index 32964a75..bb4ea131 100644
--- a/frontend/src/utils/queryAutoLimit.test.ts
+++ b/frontend/src/utils/queryAutoLimit.test.ts
@@ -32,9 +32,9 @@ describe('applyQueryAutoLimit', () => {
     ['dameng'],
     ['dm'],
     ['dm8'],
-  ])('adds FETCH FIRST limit for %s connections', (dbType) => {
+  ])('adds ROWNUM limit for %s connections', (dbType) => {
     expect(applyQueryAutoLimit('SELECT * FROM MYCIMLED.EDC_LOG', dbType, 500).sql)
-      .toBe('SELECT * FROM MYCIMLED.EDC_LOG FETCH FIRST 500 ROWS ONLY');
+      .toBe('SELECT * FROM (SELECT * FROM MYCIMLED.EDC_LOG) WHERE ROWNUM <= 500');
   });
 
   it.each([
@@ -53,8 +53,8 @@ describe('applyQueryAutoLimit', () => {
   });
 
   it.each([
-    ['oracle', 'SELECT * FROM users FETCH FIRST 500 ROWS ONLY'],
-    ['dm8', 'SELECT * FROM users FETCH FIRST 500 ROWS ONLY'],
+    ['oracle', 'SELECT * FROM (SELECT * FROM users) WHERE ROWNUM <= 500'],
+    ['dm8', 'SELECT * FROM (SELECT * FROM users) WHERE ROWNUM <= 500'],
     ['mssql', 'SELECT TOP 500 * FROM users'],
     ['postgresql', 'SELECT * FROM users LIMIT 500'],
     ['doris', 'SELECT * FROM users LIMIT 500'],
@@ -66,7 +66,12 @@ describe('applyQueryAutoLimit', () => {
 
   it('keeps trailing semicolon and comments after injected Oracle limit', () => {
     expect(applyQueryAutoLimit('SELECT * FROM MYCIMLED.EDC_LOG; -- preview', 'oracle', 500).sql)
-      .toBe('SELECT * FROM MYCIMLED.EDC_LOG FETCH FIRST 500 ROWS ONLY; -- preview');
+      .toBe('SELECT * FROM (SELECT * FROM MYCIMLED.EDC_LOG) WHERE ROWNUM <= 500; -- preview');
+  });
+
+  it('uses Oracle 11g compatible ROWNUM limit for simple table queries', () => {
+    expect(applyQueryAutoLimit('select 1 from xxx', 'oracle', 500).sql)
+      .toBe('SELECT * FROM (select 1 from xxx) WHERE ROWNUM <= 500');
   });
 
   it('does not add another generic limit when SQL already limits rows', () => {
@@ -88,6 +93,11 @@ describe('applyQueryAutoLimit', () => {
       .toBe(false);
   });
 
+  it('does not wrap Oracle FOR UPDATE queries', () => {
+    expect(applyQueryAutoLimit('SELECT * FROM users FOR UPDATE', 'oracle', 500).applied)
+      .toBe(false);
+  });
+
   it('does not add another SQL Server limit when SQL already uses TOP', () => {
     expect(applyQueryAutoLimit('SELECT TOP 10 * FROM users', 'sqlserver', 500).applied)
       .toBe(false);
diff --git a/frontend/src/utils/queryAutoLimit.ts b/frontend/src/utils/queryAutoLimit.ts
index 8b8560ce..f2e0aa72 100644
--- a/frontend/src/utils/queryAutoLimit.ts
+++ b/frontend/src/utils/queryAutoLimit.ts
@@ -320,7 +320,9 @@ export const applyQueryAutoLimit = (
     if (rownumPos >= 0) return { sql, applied: false, maxRows };
     const offsetPos = findTopLevelKeyword(main, 'offset');
     if (offsetPos >= 0 && (fromPos < 0 || offsetPos > fromPos)) return { sql, applied: false, maxRows };
-    return { sql: `${main.trimEnd()} FETCH FIRST ${maxRows} ROWS ONLY${tail}`, applied: true, maxRows };
+    const forPos = findTopLevelKeyword(main, 'for');
+    if (forPos >= 0 && (fromPos < 0 || forPos > fromPos)) return { sql, applied: false, maxRows };
+    return { sql: `SELECT * FROM (${main.trimEnd()}) WHERE ROWNUM <= ${maxRows}${tail}`, applied: true, maxRows };
   }
 
   const offsetPos = findTopLevelKeyword(main, 'offset');