The Connection URI Is Canonical; Flags Are It Decomposed

One connection URI carries all five coordinates and looks identical across engines. CLI flags are just that URI taken apart, with casing traps like -P port vs -p password.

One URI shape carries all five coordinates and looks identical across engines:

scheme://user:password@host:port/database

Postgres: postgresql://u:[email protected]:5432/db
Mongo: mongodb://u:[email protected]:27017/db
MySQL: same shape conceptually, but the mysql CLI only takes flags.

CLI flags are just this URI taken apart: -h=host, and port / user / db are the rest. The real trap is casing collisions:

psql: -p=port (lower), -U=user (upper), no password-value flag (use PGPASSWORD or the URI).
mysql: -P=port (UPPER), -p=password glued on (-pSecret; a space makes it the database name), -u=user.

From this session: psql postgresql://postgres:[email protected]:5433/demo_db worked verbatim, proof that using the URI sidesteps all flag-guessing.

Remember one URI; flags are just it taken apart. When unsure of a flag, hand it the URI.

References

PostgreSQL libpq connection: https://www.postgresql.org/docs/current/libpq-connect.html
Postgres connection strings and psql: https://tapoueh.org/blog/2019/09/postgres-connection-strings-and-psql/

Related: back to the remote DB overview; see the five coordinates and the MySQL CLI flags.

Tags #databases #cli