How to use Postgresql psql shell command line

• connection
  psql -h localhost -p 5432 -U myuser -d mydatabase
psql -h localhost -p 5432 -U myuser -d mydatabase -c 'SELECT * FROM public.mytable
  or you use sql shell
  \c mydatabase

• to list the table information :
  \d mytable

• SELECT * FROM public.mytable; \gx

Please do not forget ; at the end of your query

\bind [PARAM]... set query parameters
\copyright show PostgreSQL usage and distribution terms
\crosstabview [COLUMNS] execute query and display result in crosstab
\errverbose show most recent error message at maximum verbosity
\g [(OPTIONS)] [FILE] execute query (and send result to file or |pipe);
\g with no arguments is equivalent to a semicolon
\gdesc describe result of query, without executing it
\gexec execute query, then execute each value in its result
\gset [PREFIX] execute query and store result in psql variables
\gx [(OPTIONS)] [FILE] as \g, but forces expanded output mode
\q quit psql
\watch [[i=]SEC] [c=N] execute query every SEC seconds, up to N times

Help
\? [commands] show help on backslash commands
\? options show help on psql command-line options
\? variables show help on special variables
\h [NAME] help on syntax of SQL commands, * for all commands

Query Buffer
\e [FILE] [LINE] edit the query buffer (or file) with external editor
\ef [FUNCNAME [LINE]] edit function definition with external editor
\ev [VIEWNAME [LINE]] edit view definition with external editor
\p show the contents of the query buffer
\r reset (clear) the query buffer
\s [FILE] display history or save it to file
\w FILE write query buffer to file

Input/Output
\copy ... perform SQL COPY with data stream to the client host
\echo [-n] [STRING] write string to standard output (-n for no newline)
\i FILE execute commands from file
\ir FILE as \i, but relative to location of current script
\o [FILE] send all query results to file or |pipe
\qecho [-n] [STRING] write string to \o output stream (-n for no newline)
\warn [-n] [STRING] write string to standard error (-n for no newline)

Conditional
\if EXPR begin conditional block
\elif EXPR alternative within current conditional block
\else final alternative within current conditional block
\endif end conditional block

\dy[+] [PATTERN] list event triggers
\l[+] [PATTERN] list databases
\sf[+] FUNCNAME show a function's definition
\sv[+] VIEWNAME show a view's definition
\z[S] [PATTERN] same as \dp

Large Objects
\lo_export LOBOID FILE write large object to file
\lo_import FILE [COMMENT]
read large object from file
\lo_list[+] list large objects
\lo_unlink LOBOID delete a large object

Formatting
\a toggle between unaligned and aligned output mode
\C [STRING] set table title, or unset if none
\f [STRING] show or set field separator for unaligned query output
\H toggle HTML output mode (currently off)
\pset [NAME [VALUE]] set table output option
(border|columns|csv_fieldsep|expanded|fieldsep|
fieldsep_zero|footer|format|linestyle|null|
numericlocale|pager|pager_min_lines|recordsep|
recordsep_zero|tableattr|title|tuples_only|
unicode_border_linestyle|unicode_column_linestyle|
unicode_header_linestyle|xheader_width)
\t [on|off] show only rows (currently off)
\T [STRING] set HTML