diff --git a/apps/desktop/src/components/editor/QueryEditor.vue b/apps/desktop/src/components/editor/QueryEditor.vue
index 99b1c5eb7..e7260ec7b 100644
--- a/apps/desktop/src/components/editor/QueryEditor.vue
+++ b/apps/desktop/src/components/editor/QueryEditor.vue
@@ -25,6 +25,7 @@ import { blankLineDeletionChanges, replaceSelectedEditorText } from "@/lib/edito
 import { createSqlSignatureTooltipDom } from "@/lib/editor/sqlSignatureTooltip";
 import { buildSqlInConditionFromPasteSource, insertTextForSqlInCondition } from "@/lib/sql/sqlInListPaste";
 import { resolveSqlSingleQuoteKeyAction } from "@/lib/sql/sqlQuoteCaret";
+import { convertSqlSelectionCase, type SqlSelectionCaseMode } from "@/lib/sql/sqlSelectionCase";
 import { formatMongoShellText } from "@/lib/mongo/mongoFormatter";
 import { useConnectionStore, COMPLETION_METADATA_CONCURRENCY } from "@/stores/connectionStore";
 import { useSettingsStore } from "@/stores/settingsStore";
@@ -420,7 +421,6 @@ function runStatementGutterExtension(markers = props.statementExecutionMarkers ?
   return shouldShowStatementGutter(showRunButtons, markers.length) ? (buildRunStatementGutterExtension?.() ?? []) : [];
 }
 
-type SelectionCaseMode = "upper" | "lower";
 let executableStatementRangeCache: ExecutableStatementRangeCache | null = null;
 let editorScrollbarPointerCleanup: (() => void) | null = null;
 let editorSelectionDragCleanup: (() => void) | null = null;
@@ -1078,17 +1078,17 @@ function selectAllSqlFromContextMenu() {
   focusEditor();
 }
 
-function convertSelectedSqlCase(mode: SelectionCaseMode): boolean {
+function convertSelectedSqlCase(mode: SqlSelectionCaseMode): boolean {
   const currentView = view.value;
   const EditorSelection = codeMirrorEditorSelection;
   if (!currentView || !EditorSelection) return false;
 
   const state = currentView.state;
+  const documentText = state.doc.toString();
   const transaction = state.changeByRange((range) => {
     if (range.empty) return { range };
 
-    const selectedText = state.sliceDoc(range.from, range.to);
-    const convertedText = mode === "upper" ? selectedText.toUpperCase() : selectedText.toLowerCase();
+    const convertedText = convertSqlSelectionCase(documentText, { from: range.from, to: range.to }, mode, sqlBehaviorDialect());
     return {
       changes: { from: range.from, to: range.to, insert: convertedText },
       range: EditorSelection.range(range.from, range.from + convertedText.length),
diff --git a/apps/desktop/src/lib/__tests__/sql/sqlSelectionCase.spec.ts b/apps/desktop/src/lib/__tests__/sql/sqlSelectionCase.spec.ts
new file mode 100644
index 000000000..3b2786317
--- /dev/null
+++ b/apps/desktop/src/lib/__tests__/sql/sqlSelectionCase.spec.ts
@@ -0,0 +1,53 @@
+import { describe, expect, it } from "vitest";
+import { convertSqlSelectionCase } from "@/lib/sql/sqlSelectionCase";
+
+describe("convertSqlSelectionCase", () => {
+  it("converts SQL text without changing string literals", () => {
+    const sql = "SELECT Code FROM Orders WHERE Code = 'ABC001' AND Note = 'It''s Ready'";
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "lower")).toBe("select code from orders where code = 'ABC001' and note = 'It''s Ready'");
+  });
+
+  it("preserves string literals when converting to uppercase", () => {
+    const sql = "select code from orders where code = 'abc001'";
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "upper")).toBe("SELECT CODE FROM ORDERS WHERE CODE = 'abc001'");
+  });
+
+  it("preserves the selected fragment when the selection is inside a string literal", () => {
+    const sql = "select * from orders where code = 'AbC001'";
+    const from = sql.indexOf("bC");
+
+    expect(convertSqlSelectionCase(sql, { from, to: from + 2 }, "lower")).toBe("bC");
+  });
+
+  it("preserves PostgreSQL dollar-quoted string literals", () => {
+    const sql = "select $tag$Mixed Value$tag$ as label";
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "upper", "postgres")).toBe("SELECT $tag$Mixed Value$tag$ AS LABEL");
+  });
+
+  it("continues converting comments and quoted identifiers", () => {
+    const sql = 'select "MixedName" -- Keep Comment\nfrom users';
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "lower")).toBe('select "mixedname" -- keep comment\nfrom users');
+  });
+
+  it("uses SQL Server tokenization so temp tables do not hide later literals", () => {
+    const sql = "SELECT * FROM #Temp WHERE Code = 'AbC001'";
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "lower", "sqlserver")).toBe("select * from #temp where code = 'AbC001'");
+  });
+
+  it("preserves MySQL double-quoted strings", () => {
+    const sql = 'SELECT "Mixed Value" AS Label';
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "lower", "mysql")).toBe('select "Mixed Value" as label');
+  });
+
+  it("preserves MySQL executable comments", () => {
+    const sql = "SELECT 1 /*!40101 SET @Name = 'Mixed Value' */ FROM Dual";
+
+    expect(convertSqlSelectionCase(sql, { from: 0, to: sql.length }, "lower", "mysql")).toBe("select 1 /*!40101 SET @Name = 'Mixed Value' */ from dual");
+  });
+});
diff --git a/apps/desktop/src/lib/sql/sqlSelectionCase.ts b/apps/desktop/src/lib/sql/sqlSelectionCase.ts
new file mode 100644
index 000000000..b910be0b4
--- /dev/null
+++ b/apps/desktop/src/lib/sql/sqlSelectionCase.ts
@@ -0,0 +1,37 @@
+import { tokenizeSqlSemantic } from "@/lib/sql/semantic/tokens";
+
+export type SqlSelectionCaseMode = "upper" | "lower";
+
+type SqlSelectionRange = {
+  from: number;
+  to: number;
+};
+
+function convertCase(text: string, mode: SqlSelectionCaseMode): string {
+  return mode === "upper" ? text.toUpperCase() : text.toLowerCase();
+}
+
+export function convertSqlSelectionCase(sql: string, range: SqlSelectionRange, mode: SqlSelectionCaseMode, dialectId?: "mysql" | "postgres" | "sqlserver"): string {
+  const from = Math.max(0, Math.min(range.from, sql.length));
+  const to = Math.max(from, Math.min(range.to, sql.length));
+  const protectedTokens = tokenizeSqlSemantic(sql, dialectId).filter((item) => {
+    if (item.span.end <= from || item.span.start >= to) return false;
+    if (item.kind === "string") return true;
+    if (dialectId !== "mysql") return false;
+    if (item.kind === "quoted_identifier" && item.quote === '"') return true;
+    return item.kind === "comment" && /^\/\*(?:!|M!)/i.test(item.text);
+  });
+  if (protectedTokens.length === 0) return convertCase(sql.slice(from, to), mode);
+
+  let converted = "";
+  let cursor = from;
+  for (const item of protectedTokens) {
+    const literalFrom = Math.max(from, item.span.start);
+    const literalTo = Math.min(to, item.span.end);
+    converted += convertCase(sql.slice(cursor, literalFrom), mode);
+    converted += sql.slice(literalFrom, literalTo);
+    cursor = literalTo;
+  }
+  converted += convertCase(sql.slice(cursor, to), mode);
+  return converted;
+}