Use PL/pgSQL in PostgreSQL outside of a stored procedure or function? I'd really like to use an IF, ELSE construct and execute multiple statements within the IF and ELSE blocks, but I don't wish to save my commands to the database as a stored procedure or function. Can I do this in PostgreSQL?
There is the DO command for ad-hoc plpgsql execution.
But you cannot pass parameters or return rows directly to / from a DO command.
BTW, strictly speaking, Postgres does not have &quot;stored procedures&quot; before Postgres 11. Just functions providing very similar functionality. See:

In PostgreSQL, what is the difference between a &quot;Stored Procedure&quot; and other types of functions?