🐛 fix(query-editor): 修复 Oracle 查询自动限行语法

- 将 Oracle/Dameng 查询编辑器自动限行从 FETCH FIRST 改为 ROWNUM 兼容写法

- 识别 ROWNUM 自动封顶 SQL，避免结果分页继续基于截断 SQL 查询

- 补充自动限行与结果分页回归测试，覆盖 Oracle/Dameng 分支

frontend/src/utils/queryAutoLimit.test.ts

@@ -40,9 +40,9 @@ 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([
@@ -61,8 +61,8 @@ 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'],
     ['gauss-db', 'SELECT * FROM users LIMIT 500'],
@@ -74,19 +74,19 @@ describe('applyQueryAutoLimit', () => {
       .toBe(expected);
   });
 
-  it('keeps trailing semicolon and comments after injected Oracle limit', () => {
+  it('keeps trailing semicolon and comments after injected Oracle ROWNUM 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 FETCH FIRST limit for simple table queries', () => {
+  it('uses Oracle ROWNUM limit for simple table queries', () => {
     expect(applyQueryAutoLimit('select 1 from xxx', 'oracle', 500).sql)
-      .toBe('select 1 from xxx FETCH FIRST 500 ROWS ONLY');
+      .toBe('SELECT * FROM (select 1 from xxx) WHERE ROWNUM <= 500');
   });
 
-  it('keeps ORDER BY semantics with Oracle FETCH FIRST', () => {
+  it('keeps ORDER BY semantics with Oracle ROWNUM wrapping', () => {
     expect(applyQueryAutoLimit('SELECT * FROM users ORDER BY created_at DESC', 'oracle', 100).sql)
-      .toBe('SELECT * FROM users ORDER BY created_at DESC FETCH FIRST 100 ROWS ONLY');
+      .toBe('SELECT * FROM (SELECT * FROM users ORDER BY created_at DESC) WHERE ROWNUM <= 100');
   });
 
   it('does not add another generic limit when SQL already limits rows', () => {

frontend/src/utils/queryAutoLimit.ts

@@ -1,4 +1,5 @@
 import { resolveSqlDialect } from './sqlDialect';
+import { buildPaginatedSelectSQL } from './sql';
 
 const isWS = (ch: string) => ch === ' ' || ch === '\t' || ch === '\n' || ch === '\r';
 const isWord = (ch: string) => /[A-Za-z0-9_]/.test(ch);
@@ -322,7 +323,7 @@ export const applyQueryAutoLimit = (
     if (offsetPos >= 0 && (fromPos < 0 || offsetPos > fromPos)) return { sql, applied: false, maxRows };
     const forPos = findTopLevelKeyword(main, 'for');
     if (forPos >= 0 && (fromPos < 0 || forPos > fromPos)) return { sql, applied: false, maxRows };
-    return { sql: `${main.trimEnd()} FETCH FIRST ${maxRows} ROWS ONLY${tail}`, applied: true, maxRows };
+    return { sql: `${buildPaginatedSelectSQL(normalizedType, main, '', maxRows, 0)}${tail}`, applied: true, maxRows };
   }
 
   const offsetPos = findTopLevelKeyword(main, 'offset');

frontend/src/utils/queryResultPagination.test.ts

@@ -45,6 +45,25 @@ describe('queryResultPagination', () => {
     });
   });
 
+  it('treats query-editor injected Oracle ROWNUM wrapper as a capped page', () => {
+    const page = createInitialQueryResultPagination({
+      executedSql: 'SELECT * FROM (SELECT id, name FROM users ORDER BY created_at DESC) WHERE ROWNUM <= 500',
+      exportSql: 'SELECT id, name FROM users ORDER BY created_at DESC',
+      dbType: 'oracle',
+      returnedRowCount: 500,
+      fallbackPageSize: 500,
+    });
+
+    expect(page).toMatchObject({
+      current: 1,
+      pageSize: 500,
+      total: 500,
+      totalKnown: true,
+      baseSql: 'SELECT id, name FROM users ORDER BY created_at DESC',
+      exportAllSql: 'SELECT id, name FROM users ORDER BY created_at DESC',
+    });
+  });
+
   it('builds the next page SQL with one lookahead row', () => {
     expect(buildQueryResultPageSql({
       baseSql: 'SELECT id FROM users',

frontend/src/utils/queryResultPagination.ts

@@ -68,12 +68,29 @@ const stripExplicitLimitForExport = (sql: string): string => {
   return splitSqlTail(sql).main.trim();
 };
 
-const wasLimitAppliedByQueryEditorCap = (executedSql: string, exportSql: string): boolean => {
+const wasLimitAppliedByQueryEditorCap = (
+  executedSql: string,
+  exportSql: string,
+  dbType: string,
+  driver: string,
+  fallbackPageSize: number,
+): boolean => {
   const executed = String(executedSql || '').trim();
   const exportable = String(exportSql || '').trim();
   if (!executed || !exportable) return false;
   if (normalizeSqlForComparison(executed) === normalizeSqlForComparison(exportable)) return false;
-  return normalizeSqlForComparison(stripExplicitLimitForExport(executed)) === normalizeSqlForComparison(stripExplicitLimitForExport(exportable));
+
+  const exportBaseSql = stripExplicitLimitForExport(exportable);
+  if (normalizeSqlForComparison(stripExplicitLimitForExport(executed)) === normalizeSqlForComparison(exportBaseSql)) {
+    return true;
+  }
+
+  const pageSize = normalizePositiveInteger(fallbackPageSize);
+  if (pageSize <= 0 || getLeadingKeyword(exportBaseSql) !== 'select') return false;
+
+  const dialect = resolveSqlDialect(dbType || 'mysql', driver || '');
+  const queryEditorCappedSql = buildPaginatedSelectSQL(dialect, exportBaseSql, '', pageSize, 0);
+  return normalizeSqlForComparison(executed) === normalizeSqlForComparison(queryEditorCappedSql);
 };
 
 const resolveWrappedBaseSql = (dbType: string, baseSql: string): string => {
@@ -155,14 +172,22 @@ export const createInitialQueryResultPagination = (params: {
     : 1;
   if (current <= 1 && returnedRowCount < pageSize) return undefined;
 
-  const baseSql = explicitLimit?.baseSql || mainSql;
-  if (!baseSql) return undefined;
-
   const exportSql = String(params.exportSql || '').trim();
   const exportAllSql = exportSql && getLeadingKeyword(exportSql) === 'select'
     ? stripExplicitLimitForExport(exportSql)
     : stripExplicitLimitForExport(executedSql);
-  const autoLimitCap = current === 1 && wasLimitAppliedByQueryEditorCap(executedSql, exportSql);
+  const autoLimitCap = current === 1 && wasLimitAppliedByQueryEditorCap(
+    executedSql,
+    exportSql,
+    params.dbType,
+    params.driver || '',
+    fallbackPageSize,
+  );
+  const baseSql = autoLimitCap && exportAllSql
+    ? exportAllSql
+    : explicitLimit?.baseSql || mainSql;
+  if (!baseSql) return undefined;
+
   const totalState = autoLimitCap
     ? { total: returnedRowCount, totalKnown: true }
     : resolveQueryResultPaginationTotal({