How to select a schema in postgres when using psql?

问题

I have a postgres database with multiple schemas. When I connect to the database from a shell with psql and I run \dt it uses the default connection schema which is public. Is there a flag I can specify or how can I change the schema?

回答1:

In PostgreSQL the system determines which table is meant by following a search path, which is a list of schemas to look in.

The first matching table in the search path is taken to be the one wanted, otherwise, if there is no match a error is raised, even if matching table names exist in other schemas in the database.

To show the current search path you can use the following command:

SHOW search_path;

And to put the new schema in the path, you could use:

SET search_path TO myschema;

Or if you want multiple schemas:

SET search_path TO myschema, public;

Reference: https://www.postgresql.org/docs/current/static/ddl-schemas.html

回答2:

Do you want to change database?

\l - to display databases
\c - connect to new database

Update.

I've read again your question. To display schemas

\dn - list of schemas

To change schema, you can try

SET search_path TO

回答3:

Use schema name with period in psql command to obtain information about this schema.

Setup:

test=# create schema test_schema;
CREATE SCHEMA
test=# create table test_schema.test_table (id int);
CREATE TABLE
test=# create table test_schema.test_table_2 (id int);
CREATE TABLE

Show list of relations in test_schema:

test=# \dt test_schema.
               List of relations
   Schema    |     Name     | Type  |  Owner   
-------------+--------------+-------+----------
 test_schema | test_table   | table | postgres
 test_schema | test_table_2 | table | postgres
(2 rows)

Show test_schema.test_table definition:

test=# \d test_schema.test_table
Table "test_schema.test_table"
 Column |  Type   | Modifiers 
--------+---------+-----------
 id     | integer |

Show all tables in test_schema:

test=# \d test_schema.
Table "test_schema.test_table"
 Column |  Type   | Modifiers 
--------+---------+-----------
 id     | integer | 

Table "test_schema.test_table_2"
 Column |  Type   | Modifiers 
--------+---------+-----------
 id     | integer |

etc...

回答4:

\l - Display database
\c - Connect to database
\dn - List schemas
\dt - List tables inside public schemas
\dt schema1. - List tables inside particular schemas. For eg: 'schema1'.

回答5:

This is old, but I put exports in my alias for connecting to the db:

alias schema_one.con="PGOPTIONS='--search_path=schema_one' psql -h host -U user -d database etc"

And for another schema:

alias schema_two.con="PGOPTIONS='--search_path=schema_two' psql -h host -U user -d database etc"

回答6:

key word :

SET search_path TO

example :

SET search_path TO your_schema_name;

回答7:

quick solution could be:

SELECT your_db_column_name from "your_db_schema_name"."your_db_tabel_name";

来源：https://stackoverflow.com/questions/34098326/how-to-select-a-schema-in-postgres-when-using-psql

标签

postgresql

psql