SQL Syntax Errors referencing a $1 placeholder

[afair]

When running a query using an association, ActiveRecord has changed to use prepared statements with bind parameters, something like:

"select * from  comments where post_id = $1", [["post_id", 123]]

so when to_sql is called on the relation, the $1 is not yet interpolated.

Solution: use connection.unprepared_statement { to_sql } syntax to skip preparation. Cursor declaration includes preparation anyway.