.schema for postgres
I'm migrating a database from sqlite3 to postgres and am wondering if there are any short tutorials that can teach me the new syntax.
Also, as a short term question, how do I see the schema of a postgres table which is e开发者_StackOverflow社区quivalent to .schema
in sqlite?
You could use pg_dump command line utility, i.e.:
pg_dump --table <table_name> --schema-only <database_name>
Depending on your environment you probably need to specify connection options (-h, -p, -U switches).
You could use \d
from within psql
:
=> \?
...
Informational
(options: S = show system objects, + = additional detail)
\d[S+] list tables, views, and sequences
\d[S+] NAME describe table, view, sequence, or index
...
=> \d people
Table "public.people"
Column | Type | Modifiers
------------------------+-----------------------------+-----------------------------------------------------
id | integer | not null default nextval('people_id_seq'::regclass)
created_at | timestamp without time zone | not null
updated_at | timestamp without time zone | not null
...
Indexes:
"people_pkey" PRIMARY KEY, btree (id)
...
Check constraints:
"chk_people_latlng" CHECK ((lat IS NULL) = (lng IS NULL))
....
You can also root around in the information_schema
if you're not inside psql
.
If you are using psql (and \d... ) then you can
\set ECHO_HIDDEN
to see the sql for the queries that psql is executing to put together the \d... output-- this is useful not only as sql syntax examples but it also shows you where find, and how to connect, the database metadata.
To get the schema name for a table you can:
SELECT n.nspname AS schema_name,
c.relname AS table_name
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relname = '<table_name>'
;
(don't know how that compares to .schema)
Maybe you can use a PostgreSQL Cheat Sheet:
http://www.postgresonline.com/special_feature.php?sf_name=postgresql83_cheatsheet&outputformat=html
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