fix(structure): unquote plain Oracle identifiers when quoting off

apps/desktop/src/components/structure/TableStructureEditor.vue

@@ -27,7 +27,7 @@ import { createDbxCodeMirrorSqlDialect } from "@/lib/editor/codemirrorSqlDialect
 import { useToast } from "@/composables/useToast";
 import { type SqlHighlighter, createShikiSqlHighlighter } from "@/lib/sql/sqlHighlighter";
 import { joinSqlStatementsForScript } from "@/lib/sql/sqlBatchScript";
-import { omitDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
+import { formatGeneratedDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
 import { splitSqlStatementRanges } from "@/lib/sql/sqlStatementRanges";
 import { copyToClipboard } from "@/lib/common/clipboard";
 import { formatSqlForDisplay, sqlFormatDialectForDbType } from "@/lib/sql/sqlFormatter";
@@ -1767,7 +1767,7 @@ async function refreshSqlPreview() {
     if (requestId !== sqlPreviewRequestId) return;
     const statements = [...result.statements, ...ownerResult.statements, ...(mysqlAutoIncrementStatement ? [mysqlAutoIncrementStatement] : [])];
     // SQLite type-change apply regenerates this revision-checked plan, so its preview must stay byte-for-byte aligned.
-    pendingStatements.value = settingsStore.editorSettings.generateSqlQuoteIdentifiers || hasSqliteTypeChange.value ? statements : statements.map((statement) => omitDdlIdentifierQuotes(statement, sqlFormatDialectForDbType(databaseType.value)));
+    pendingStatements.value = settingsStore.editorSettings.generateSqlQuoteIdentifiers !== false || hasSqliteTypeChange.value ? statements : statements.map((statement) => formatGeneratedDdlIdentifierQuotes(statement, sqlFormatDialectForDbType(databaseType.value), false));
     warnings.value = [...result.warnings, ...ownerResult.warnings];
     sqliteSchemaRevision.value = "schemaRevision" in result && typeof result.schemaRevision === "string" ? result.schemaRevision : undefined;
   } catch (e: any) {

apps/desktop/src/lib/sql/__tests__/ddlDisplay.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { omitDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
+import { formatGeneratedDdlIdentifierQuotes, omitDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
 
 describe("omitDdlIdentifierQuotes", () => {
   it("removes safe MySQL identifier quotes without changing literals or comments", () => {
@@ -40,4 +40,19 @@ describe("omitDdlIdentifierQuotes", () => {
     const ddl = 'CREATE TABLE "CamelCase" ("lowercase" INT, "WITH SPACE" INT, "ORDER" INT, "A$B" INT)';
     expect(omitDdlIdentifierQuotes(ddl, "dameng")).toBe(ddl);
   });
+
+  it("folds safe Oracle identifiers when generated SQL quoting is disabled", () => {
+    const ddl = 'ALTER TABLE "SYSTEM"."TEST" RENAME COLUMN "ABCD" TO "AbCd";';
+    expect(formatGeneratedDdlIdentifierQuotes(ddl, "oracle", false)).toBe("ALTER TABLE SYSTEM.TEST RENAME COLUMN ABCD TO ABCD;");
+  });
+
+  it("keeps case-sensitive Dameng identifiers quoted when generated SQL quoting is disabled", () => {
+    const ddl = 'ALTER TABLE "user_login_log" ADD "status" INT; ALTER TABLE "CamelCase" ADD "order" INT;';
+    expect(formatGeneratedDdlIdentifierQuotes(ddl, "dameng", false)).toBe(ddl);
+  });
+
+  it("preserves generated identifier quotes when the setting is enabled", () => {
+    const ddl = 'ALTER TABLE "SYSTEM"."TEST" RENAME COLUMN "ABCD" TO "AbCd";';
+    expect(formatGeneratedDdlIdentifierQuotes(ddl, "oracle", true)).toBe(ddl);
+  });
 });

apps/desktop/src/lib/sql/ddlDisplay.ts

@@ -43,3 +43,34 @@ export function omitDdlIdentifierQuotes(sql: string, dialect: SqlFormatDialect):
   }
   return result;
 }
+
+const SIMPLE_ORACLE_IDENTIFIER = /^[A-Za-z_][A-Za-z0-9_$#]*$/;
+
+/**
+ * Applies the identifier-quoting preference to SQL generated by a structure
+ * editor. Oracle folds bare identifiers to uppercase, so safe quoted names
+ * are uppercased before their quotes are removed. Dameng keeps its stricter
+ * case-sensitive identifier rules through omitDdlIdentifierQuotes instead.
+ */
+export function formatGeneratedDdlIdentifierQuotes(sql: string, dialect: SqlFormatDialect, quoteIdentifiers: boolean): string {
+  if (quoteIdentifiers) return sql;
+  if (dialect !== "oracle") return omitDdlIdentifierQuotes(sql, dialect);
+
+  const tokens = tokenizeSqlSemantic(sql, dialect);
+  const replacements: Array<{ start: number; end: number; value: string }> = [];
+
+  for (const token of tokens) {
+    if (token.kind !== "quoted_identifier") continue;
+    const identifier = unquoteSqlSemanticIdentifier(token);
+    if (SIMPLE_ORACLE_IDENTIFIER.test(identifier) && !requiresOracleIdentifierQuote(identifier.toUpperCase())) {
+      replacements.push({ start: token.span.start, end: token.span.end, value: identifier.toUpperCase() });
+    }
+  }
+
+  let result = sql;
+  for (let index = replacements.length - 1; index >= 0; index -= 1) {
+    const replacement = replacements[index]!;
+    result = `${result.slice(0, replacement.start)}${replacement.value}${result.slice(replacement.end)}`;
+  }
+  return result;
+}