SQLAlchemy 2.0: 'Textual SQL expression ... should be explicitly declared as text(...)' or conn.execute('SELECT ...') failing after upgrading from 1.x

Cause: SQLAlchemy 2.0 stopped accepting bare strings as SQL in places where 1.x tolerated them. Connection.execute() no longer takes a plain string (it was deprecated in 1.4), and passing a raw string where a SQL expression is expected now raises an error telling you to declare it with text(). The migration notes explain the reason: Session.execute() already converted strings to text() while Connection.execute() passed them straight to the driver, so 2.0 made the behaviour consistent. Fix (best first): 1. Wrap literal SQL in text(): from sqlalchemy import text, then conn.execute(text("SELECT id, name FROM users WHERE id = :id"), {"id": 5}). Use named :param placeholders and pass values as a dict instead of formatting them into the string; this also avoids SQL injection from string building. 2. If you really need driver-level paramstyle (for example %s or ? placeholders), use Connection.exec_driver_sql() instead of text(). 3. Prefer expression constructs where possible (select(User).where(...)) and use text() only for fragments you cannot express otherwise, for example .where(text("created_at > now()")). 4. Remember 2.0 also changed transactions: Connection autobegins and does not autocommit, so after INSERT/UPDATE text statements call conn.commit(), or use with engine.begin() as conn: which commits on success and rolls back on exception. 5. To find remaining 1.x-style usage before upgrading, run your tests on 1.4 with the SQLALCHEMY_WARN_20=1 environment variable, or upgrade and fix the errors one by one. Verify: the statement runs under SQLAlchemy 2.x (python -c "import sqlalchemy; print(sqlalchemy.__version__)"), and writes made through text() persist after the connection closes. Sources: https://docs.sqlalchemy.org/en/20/changelog/migration_20.html https://docs.sqlalchemy.org/en/20/core/connections.html