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Post date: Dec 03, 2014 8:6:3 PM
One of the most frequent question asked by Newbies that what is the syntax of a command like create table, create index etc. It is easily available through online help. Here is how.
[gpadmin@sachi scripts]$ psql --help
This is psql 8.2.15, the PostgreSQL interactive terminal (Greenplum version).
Usage:
psql [OPTION]... [DBNAME [USERNAME]]
General options:
-c, --command=COMMAND run only single command (SQL or internal) and exit
-d, --dbname=DBNAME database name to connect to (default: "gpadmin")
-f, --file=FILENAME execute commands from file, then exit
-l, --list list available databases, then exit
-v, --set=, --variable=NAME=VALUE
set psql variable NAME to VALUE
-X, --no-psqlrc do not read startup file (~/.psqlrc)
-1 ("one"), --single-transaction
execute command file as a single transaction
--help show this help, then exit
--version output version information, then exit
Input and output options:
-a, --echo-all echo all input from script
-e, --echo-queries echo commands sent to server
-E, --echo-hidden display queries that internal commands generate
-L, --log-file=FILENAME send session log to file
-n, --no-readline disable enhanced command line editing (readline)
-o, --output=FILENAME send query results to file (or |pipe)
-q, --quiet run quietly (no messages, only query output)
-s, --single-step single-step mode (confirm each query)
-S, --single-line single-line mode (end of line terminates SQL command)
Output format options:
-A, --no-align unaligned table output mode
-F, --field-separator=STRING
set field separator (default: "|")
-H, --html HTML table output mode
-P, --pset=VAR[=ARG] set printing option VAR to ARG (see \pset command)
-R, --record-separator=STRING
set record separator (default: newline)
-t, --tuples-only print rows only
-T, --table-attr=TEXT set HTML table tag attributes (e.g., width, border)
-x, --expanded turn on expanded table output
Connection options:
-h, --host=HOSTNAME database server host or socket directory (default: "local socket")
-p, --port=PORT database server port (default: "5432")
-U, --username=USERNAME database user name (default: "gpadmin")
-w, --no-password never prompt for password
-W, --password force password prompt (should happen automatically)
For more information, type "\?" (for internal commands) or "\help" (for SQL commands) from within psql, or consult the psql section in the PostgreSQL
documentation.
Report bugs to <pgsql-bugs@postgresql.org>.
or from the psql command prompt.
sachi=# \?
General
\copyright show PostgreSQL usage and distribution terms
\g [FILE] or ; execute query (and send results to file or |pipe)
\h [NAME] help on syntax of SQL commands, * for all commands
\q quit psql
Query Buffer
\e [FILE] edit the query buffer (or file) with external editor
\ef [FUNCNAME] edit function 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 [STRING] write string to standard output
\i FILE execute commands from file
\o [FILE] send all query results to file or |pipe
\qecho [STRING] write string to query output stream (see \o)
Informational
(options: S = show system objects, + = additional detail)
\d[S+] list tables, views, and sequences
\d[S+] NAME describe table, view, sequence, or index
\da[S] [PATTERN] list aggregates
\db[+] [PATTERN] list tablespaces
\dc[S] [PATTERN] list conversions
\dC [PATTERN] list casts
\dd[S] [PATTERN] show comments on objects
\ddp [PATTERN] list default privileges
\dD[S] [PATTERN] list domains
\des[+] [PATTERN] list foreign servers
\deu[+] [PATTERN] list user mappings
\dew[+] [PATTERN] list foreign-data wrappers
\df[antw][S+] [PATRN] list [only agg/normal/trigger/window] functions
\dF[+] [PATTERN] list text search configurations
\dFd[+] [PATTERN] list text search dictionaries
\dFp[+] [PATTERN] list text search parsers
\dFt[+] [PATTERN] list text search templates
\dg[+] [PATTERN] list roles (groups)
\di[S+] [PATTERN] list indexes
\dl list large objects, same as \lo_list
\dn[+] [PATTERN] list schemas
\do[S] [PATTERN] list operators
\dp [PATTERN] list table, view, and sequence access privileges
\dr[S+] [PATTERN] list foreign tables
\drds [PATRN1 [PATRN2]] list per-database role settings
\ds[S+] [PATTERN] list sequences
\dt[S+] [PATTERN] list tables
\dT[S+] [PATTERN] list data types
\du[+] [PATTERN] list roles (users)
\dv[S+] [PATTERN] list views
\dx [PATTERN] list external tables
\l[+] list all databases
\z [PATTERN] same as \dp
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
(NAME := {format|border|expanded|fieldsep|footer|null|
numericlocale|recordsep|tuples_only|title|tableattr|pager})
\t [on|off] show only rows (currently off)
\T [STRING] set HTML <table> tag attributes, or unset if none
\x [on|off] toggle expanded output (currently off)
Connection
\c[onnect] [DBNAME|- USER|- HOST|- PORT|-]
connect to new database (currently "sachi")
\encoding [ENCODING] show or set client encoding
\password [USERNAME] securely change the password for a user
\conninfo display information about current connection
Operating System
\cd [DIR] change the current working directory
\timing [on|off] toggle timing of commands (currently off)
\! [COMMAND] execute command in shell or start interactive shell
Variables
\prompt [TEXT] NAME prompt user to set internal variable
\set [NAME [VALUE]] set internal variable, or list all if no parameters
\unset NAME unset (delete) internal variable
Large Objects
\lo_export LOBOID FILE
\lo_import FILE [COMMENT]
\lo_list
\lo_unlink LOBOID large object operations
sachi=#
Finding SYNTAX for most commonly used command.
sachi=# \h create table
Command: CREATE TABLE
Description: define a new table
Syntax:
CREATE [[GLOBAL | LOCAL] {TEMPORARY | TEMP}] TABLE table_name (
[ { column_name data_type [ DEFAULT default_expr ] [column_constraint [ ... ]
[ ENCODING ( storage_directive [,...] ) ]
]
| table_constraint
| LIKE other_table [{INCLUDING | EXCLUDING}
{DEFAULTS | CONSTRAINTS}] ...}
[, ... ] ]
[column_reference_storage_directive [, �] ]
)
[ INHERITS ( parent_table [, ... ] ) ]
[ WITH ( storage_parameter=value [, ... ] )
[ ON COMMIT {PRESERVE ROWS | DELETE ROWS | DROP} ]
[ TABLESPACE tablespace ]
[ DISTRIBUTED BY (column, [ ... ] ) | DISTRIBUTED RANDOMLY ]
[ PARTITION BY partition_type (column)
[ SUBPARTITION BY partition_type (column) ]
[ SUBPARTITION TEMPLATE ( template_spec ) ]
[...]
( partition_spec )
| [ SUBPARTITION BY partition_type (column) ]
[...]
( partition_spec
[ ( subpartition_spec
[(...)]
) ]
)
where storage_parameter is:
APPENDONLY={TRUE|FALSE}
BLOCKSIZE={8192-2097152}
ORIENTATION={COLUMN|ROW}
COMPRESSTYPE={ZLIB|QUICKLZ|RLE_TYPE|NONE}
COMPRESSLEVEL={0-9}
FILLFACTOR={10-100}
OIDS[=TRUE|FALSE]
where column_constraint is:
[CONSTRAINT constraint_name]
NOT NULL | NULL
| UNIQUE [USING INDEX TABLESPACE tablespace]
[WITH ( FILLFACTOR = value )]
| PRIMARY KEY [USING INDEX TABLESPACE tablespace]
[WITH ( FILLFACTOR = value )]
| CHECK ( expression )
and table_constraint is:
[CONSTRAINT constraint_name]
UNIQUE ( column_name [, ... ] )
[USING INDEX TABLESPACE tablespace]
[WITH ( FILLFACTOR=value )]
| PRIMARY KEY ( column_name [, ... ] )
[USING INDEX TABLESPACE tablespace]
[WITH ( FILLFACTOR=value )]
| CHECK ( expression )
where partition_type is:
LIST
| RANGE
where partition_specification is:
partition_element [, ...]
and partition_element is:
DEFAULT PARTITION name
| [PARTITION name] VALUES (list_value [,...] )
| [PARTITION name]
START ([datatype] 'start_value') [INCLUSIVE | EXCLUSIVE]
[ END ([datatype] 'end_value') [INCLUSIVE | EXCLUSIVE] ]
[ EVERY ([datatype] [number | INTERVAL] 'interval_value') ]
| [PARTITION name]
END ([datatype] 'end_value') [INCLUSIVE | EXCLUSIVE]
[ EVERY ([datatype] [number | INTERVAL] 'interval_value') ]
[ WITH ( partition_storage_parameter=value [, ... ] ) ]
[column_reference_storage_directive [, ...] ]
[ TABLESPACE tablespace ]
where subpartition_spec or template_spec is:
subpartition_element [, ...]
and subpartition_element is:
DEFAULT SUBPARTITION name
| [SUBPARTITION name] VALUES (list_value [,...] )
| [SUBPARTITION name]
START ([datatype] 'start_value') [INCLUSIVE | EXCLUSIVE]
[ END ([datatype] 'end_value') [INCLUSIVE | EXCLUSIVE] ]
[ EVERY ([datatype] [number | INTERVAL] 'interval_value') ]
| [SUBPARTITION name]
END ([datatype] 'end_value') [INCLUSIVE | EXCLUSIVE]
[ EVERY ([datatype] [number | INTERVAL] 'interval_value') ]
[ WITH ( partition_storage_parameter=value [, ... ] ) ]
[column_reference_storage_directive [, ...] ]
[ TABLESPACE tablespace ]
where storage_directive is:
COMPRESSTYPE={ZLIB | QUICKLZ | RLE_TYPE | NONE}
| COMPRESSLEVEL={0-9}
| BLOCKSIZE={8192-2097152}
Where column_reference_storage_directive is:
COLUMN column_name ENCODING ( storage_directive [, ... ] ), ...
| DEFAULT COLUMN ENCODING ( storage_directive [, ... ] )
sachi=# \h analyze
Command: ANALYZE
Description: collect statistics about a database
Syntax:
ANALYZE [ VERBOSE ] [ table [ (column [, ...] ) ] ]
[gpadmin@sachi scripts]$ \h create index
-bash: h: command not found
[gpadmin@sachi scripts]$ psql -d sachi
psql (8.2.15)
Type "help" for help.
sachi=# \h create index
Command: CREATE INDEX
Description: define a new index
Syntax:
CREATE [UNIQUE] INDEX name ON table
[USING btree|bitmap|gist]
( {column | (expression)} [opclass] [, ...] )
[ WITH ( FILLFACTOR = value ) ]
[TABLESPACE tablespace]
[WHERE predicate]