src: return undefined if no rows are returned in SQLite

For now, { key: null, value: null} is returned even though
no rows are returned from database when `statement.get()`
is called. So return empty value if return value of
`sqlite3_step` is `SQLITE_DONE`.

PR-URL: nodejs#53981
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Yagiz Nizipli <[email protected]>

src/node_sqlite.cc

@@ -480,7 +480,8 @@ void StatementSync::Get(const FunctionCallbackInfo<Value>& args) {
 
   auto reset = OnScopeLeave([&]() { sqlite3_reset(stmt->statement_); });
   r = sqlite3_step(stmt->statement_);
-  if (r != SQLITE_ROW && r != SQLITE_DONE) {
+  if (r == SQLITE_DONE) return;
+  if (r != SQLITE_ROW) {
     THROW_ERR_SQLITE_ERROR(env->isolate(), stmt->db_);
     return;
   }

test/parallel/test-sqlite.js

@@ -219,7 +219,9 @@ suite('StatementSync() constructor', () => {
 suite('StatementSync.prototype.get()', () => {
   test('executes a query and returns undefined on no results', (t) => {
     const db = new DatabaseSync(nextDb());
-    const stmt = db.prepare('CREATE TABLE storage(key TEXT, val TEXT)');
+    let stmt = db.prepare('CREATE TABLE storage(key TEXT, val TEXT)');
+    t.assert.strictEqual(stmt.get(), undefined);
+    stmt = db.prepare('SELECT * FROM storage');
     t.assert.strictEqual(stmt.get(), undefined);
   });