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psql

Feb 14, 2025, 2 min read

📂 Tooling

Basic Commands

  • psql -d DB -U ROLE -h HOST -p PORT: run psql and Connect.
  • \h : List server SQL commands.
  • \h ALTER TABLE : Get syntax for specified SQL command.
  • \? : List psql commands.
  • \q : Quit psql.
  • \conninfo : Check connection.
  • \c , \connect : Connect from inside psql.
  • \! pwd : Execute shell commands.
  • \o dev1_psql.log : Output results of subsequent query to the specified file.
    • \o : Switch output back to console.
  • \i dev1_psql.log : Run SQL commands from the file.
    • psql < filename , psql -f filename : Another way to run SQL from file.
  • \dn (describe namespace): show list of schemas
    • \dnS : also show system schemas
  • \dt public.* : show all tables in public schema.
  • \dT: show all types.
  • \db : list of tablespaces.
  • \timing on, \timing off : turn on/off timing.

Formatting Options

  • \a : Toggle alignment.
  • \t : Toggle header and summary.
  • \pset : psql formatting options.
    • \pset fieldsep '' : use '' instead of | as field separator.
# Format results as single "record" - add \gx instead of ; at the end of query:
SELECT name, setting, unit, category, context, vartype, min_val, max_val, boot_val, reset_val 
FROM pg_settings 
WHERE name = 'work_mem' \gx

Variables

  • \set TEST Hello : Set value of psql variable TEST equal to Hello!.
  • \echo :TEST : Print variable value.
  • \unset TEST : Unset variable value.
  • :top5 : Run SQL statement from variable.
  • \gset : Save query results in variable, e.g. SELECT current_setting('work_mem') AS current_work_mem \gset - result will be stored in current_work_mem .
  • \set : List all variables.
  • \? variables : Info about built-in variables.

📂 Tooling | Последнее изменение: 14.04.2024 14:28

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