пт, 14 дек. 2018 г. в 14:33, Oleg <lego12239(at)yandex(dot)ru>:
>
> Hi, all.
>
> Do we really need a numeric value placeholders like $1 in command string?
It's a syntax defined at the backend side.
(https://www.postgresql.org/docs/current/sql-prepare.html)
> Construction of such string for complex non-static queries is very annoying.
That's why there are libraries like Pgfe
(https://github.com/dmitigr/pgfe) or libpqtypes
(http://libpqtypes.esilo.com/)
> Why do we can't simply use $$ placeholder, which take the next value from an
> array of values?
Because $$ means a dollar-quoted opening tag
(https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-DOLLAR-QUOTING)