fix(sql): preserve database quoting in star expansion

Closes #6247

apps/desktop/src/lib/__tests__/sql/semantic/completion.spec.ts

@@ -417,6 +417,33 @@ WHERE a.id = b.fk_kpi_set_score_id`,
     expect(star?.apply).toBe("id, u.name");
   });
 
+  it.each([
+    ["Oracle", "oracle", "mysql", '"ID", o."created at", o."SELECT", o.safe_name'],
+    ["MySQL", "mysql", "mysql", "`ID`, o.`created at`, o.`SELECT`, o.safe_name"],
+    ["PostgreSQL", "postgres", "postgres", '"ID", o."created at", o."SELECT", o.safe_name'],
+    ["SQL Server", "sqlserver", "sqlserver", "[ID], o.[created at], o.[SELECT], o.safe_name"],
+    ["dialect fallback", undefined, "mysql", "`ID`, o.`created at`, o.`SELECT`, o.safe_name"],
+  ] as const)("uses %s identifier quoting in qualified star completion items", (_label, databaseType, dialect, expected) => {
+    const columnsByTable = new Map<string, SqlCompletionColumn[]>([["orders", ["ID", "created at", "SELECT", "safe_name"].map((name) => ({ name, table: "orders" }))]]);
+
+    const starItems = semanticCompletion("SELECT o.*| FROM orders o", { columnsByTable }, { databaseType, dialect }).items;
+    const selectAllItems = semanticCompletion("SELECT o.| FROM orders o", { columnsByTable }, { databaseType, dialect }).items;
+
+    expect(starItems.find((item) => item.label === "* \u2192 columns")?.apply).toBe(expected);
+    expect(selectAllItems.find((item) => item.label === "o.*")?.apply).toBe(expected);
+  });
+
+  it("uses Oracle quoting for an unqualified multi-table star completion item", () => {
+    const columnsByTable = new Map<string, SqlCompletionColumn[]>([
+      ["ORDERS", ["ID", "created at"].map((name) => ({ name, table: "ORDERS" }))],
+      ["AUDIT", ["ID", "SELECT"].map((name) => ({ name, table: "AUDIT" }))],
+    ]);
+
+    const { items } = semanticCompletion("SELECT *| FROM ORDERS o JOIN AUDIT a ON a.ID = o.ID", { columnsByTable }, { databaseType: "oracle", dialect: "mysql" });
+
+    expect(items.find((item) => item.label === "* \u2192 columns")?.apply).toBe('o."ID", o."created at", a."ID", a."SELECT"');
+  });
+
   it("generates collision-free table aliases from semantic row sources", () => {
     const { items } = semanticCompletion("SELECT * FROM order_items oi JOIN ord|", {
       tables: [{ name: "order_items", type: "table" }],