PostgreSQL: Drop Database but DB is still there [duplicate] - postgresql

This question already has answers here:
In psql, why do some commands have no effect?
(2 answers)
Closed 2 years ago.
I am new to PostgreSQL and I try to get my head around it. I am familiar to db's and MySQL.
I am trying to delete database, which I created since psql seems to ignore the changes I try to push through Django.
When I execute \l I get the following response:
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
------------------+--------+----------+-------------+-------------+-------------------
postgres | neurix | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 |
test_db | neurix | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 |
template0 | neurix | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 | =c/neurix +
| | | | | neurix=CTc/neurix
template1 | neurix | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 | =c/neurix +
| | | | | neurix=CTc/neurix
template_postgis | neurix | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 |
(5 rows)
Now I wan to drop the database "test_db" with
DROP DATABASE test_db
but when I execute \l afterwards, the table is still there and the overview looks like about.

Did you type a ; after the DROP DATABASE test_db? Did PostgreSQL print a response to your command?

I had a similar issue when working on a Rails 6 application in Ubuntu 20.04 with PostgreSQL as my database.
When I run the command:
DROP DATABASE my-db;
The database is dropped successfully, however, the schema for the database is still left.
So when I run the command:
CREATE DATABASE my-db;
And I check the tables in the newly created database, I realized they still contained the same tables as the previously deleted database, even though I have not run any migration.
Here's how I fixed it:
Instead of running the command:
DROP DATABASE my-db;
run the command:
DROP DATABASE IF EXISTS my-db;
This deletes the database and it's corresponding schema.
That's all.
I hope this helps

Related

Postgresql error database does not exist however it exists when listing the databases

When I drop the database I have an error that it doesn't exist however when I list the databases I can see it.
Here are the steps I am following:
sudo -u postgres psql
postgres=# \l
postgres=# DROP DATABASE IF EXISTS mydbname;
NOTICE: database "mydbname" does not exist, skipping
DROP DATABASE
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
--------------------+---------------+----------+---------+---------+----------------------------
mydbname | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =Tc/postgres +
| | | | | postgres=CTc/postgres +
| | | | | cryptouser=CTc/postgres

relation *db_name* does not exist postgres

I am trying to set up an ubuntu server with postgres(following digitalocean tuorial).
I ssh'd to the server as root user, from there created a user named 'justin', gave that user admin privileges as instructed. Switched to 'justin', installed python, django, pip, etc and postgres. From here the tutorial said type sudo -u postgres psql
, I did this. From here I created a db 'jobzumodb' and user 'jobzumojustin'. I am now trying to grant privileges of that db to this new user: GRANT ALL PRIVILEGES ON jobzumodb TO jobzumojustin; and it returns ERROR: relation "jobzumodb" does not exist. However if I postgres=# \l I see:
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+---------+---------+-----------------------
jobzumodb | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =Tc/postgres +
| | | | | postgres=CTc/postgres+
| | | | | admin=CTc/postgres
postgres | postgres | UTF8 | C.UTF-8 | C.UTF-8 |
Anyone know what is causing this?
Note: when I created the db I created it with: CREATE DATABASE jobzumoDB;. And was trying to access it for a long time as 'jobzumoDB' and not 'jobzumodb', before learning the \l command and that it saved as 'jobzumodb' because I did not pass it in quotes. Anyway, not sure if this could be having an effect.
Thanks for any help.
Another edit: upon rereading this I realized I am using the 'postgres' user (I see postgres=#), should I be using the 'jobzumojustin' user and jobzumojustin=# ? Also, I checked to see if 'jobzumojustin' exists, it does, but does not have anything listed under 'list of roles and attributes'.
I think you forgot the database keyword. It should be:
GRANT ALL PRIVILEGES ON DATABASE jobzumodb TO jobzumojustin;

POSTGRESQL : Old owner present on new installation

I want to flush this DB so that the old owner doesn't exist anymore and I want to be the superuser.
I am using an ex-colleagues laptop ( mac )
PostgreSQL ( psql ) was installed via Homebrew ( 9.6 ) which I have removed as I required ( 9.5 ).
A few "perhaps" issues I've noticed:
psql9.5 is now installed and when I attempt to login I receive the following FATAL: role "MY NAME" does not exist
eventually login and when I "\l" I see the following:
DB_NAME-> \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+--------------+----------+-------------+-------------+-------------------------------
DB_NAME | DB_NAME | UTF8 | en_GB.UTF-8 | en_GB.UTF-8 |
postgres | EX COLLEAGUE | UTF8 | en_GB.UTF-8 | en_GB.UTF-8 |
template0 | EX COLLEAGUE | UTF8 | en_GB.UTF-8 | en_GB.UTF-8 | =c/EX COLLEAGUE +
| | | | | EX COLLEAGUE=CTc/EX COLLEAGUE
template1 | EX COLLEAGUE | UTF8 | en_GB.UTF-8 | en_GB.UTF-8 | =c/EX COLLEAGUE +
| | | | | EX COLLEAGUE=CTc/EX COLLEAGUE
when I run:
DB_NAME=> \du
List of roles
Role name | Attributes | Member of
--------------+------------------------------------------------------------+-----------
DB_NAME | Create DB | {}
EX COLLEAGUE | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
I can't create new Roles.
I might be over-exaggerating the severity of this - but I have no idea what to do.
I have looked at old resources and maybe I was searching incorrectly but I found no help.
Solved - had to re-install my Mac OS but was hoping for a less time consuming option

PostgreSQL can't create user [duplicate]

This question already has answers here:
In psql, why do some commands have no effect?
(2 answers)
Closed 3 years ago.
Issue: I can create users or databases from the shell (bash, OSX) but not postgres cli. From bash I get no confirmation if successful.
If I try to CREATE ROLE in psql then I get no response and it doesn't generate any error. If I try to createuser from bash then if successful it reports back nothing, if unsuccessful then it does generate the error: "role username already exists".
Example:
Yunti-# CREATE ROLE testuser
Yunti-# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
Yunti | Superuser, Create role, Create DB, Replication | {}
anything | | {}
monkey | | {}
Yunti-# CREATE DATABASE testdb
Yunti-# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+-------+----------+-------------+-------------+-------------------
Yunti | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
postgres | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
template0 | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/Yunti +
| | | | | Yunti=CTc/Yunti
template1 | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/Yunti +
| | | | | Yunti=CTc/Yunti
test | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
test5 | Yunti | UTF8 | en_US.UTF-8 | en_US.UTF-8 |
(6 rows)
Yunti-#
A similar thing happens when using createdb.
How can I create users and databases in postgres cli?
And is this normal to get no response to most postgres commands in bash?
Info: users and their privileges:
Yunti-# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------+-----------
Yunti | Superuser, Create role, Create DB, Replication | {}
anything | | {}
monkey | | {}
Your statements are not executed, because you don't terminate them properly using a ;.
Quote from the manual:
A command is composed of a sequence of tokens, terminated by a semicolon (";").
And in the manual for psql:
At the prompt, the user can type in SQL commands. Ordinarily, input lines are sent to the server when a command-terminating semicolon is reached. An end of line does not terminate a command. Thus commands can be spread over several lines for clarity. If the command was sent and executed without error, the results of the command are displayed on the screen.
If you do that, you get an output like this:
psql (9.4.4)
Type "help" for help.
postgres=# CREATE ROLE testuser;
CREATE ROLE ---<<<< this tells you the statement was executed
postgres=#
I dont know if the postgres client is using other commands in OSX as it is in Linux but I assume it is the same.
This docs link shows some options for the postgres client:
It seems like "\l" lists the databases while the option you would like to see is roles and their access which is "\du".
When creating a database from within the client you should get a response in the form of "CREATING DATABASE". Maybe you are having some sort of syntax error?
I don't think users is created elsewhere.
I hope this solves some of your problems.

Description of PostgreSQL database tables installed on a particular computer

A bit over a year ago I installed PostgreSQL on six computers. On one of those computers, I imported 2 gig of census data from CSV files.
Historically I have just worked with flat files, but in this case the files are so big they choke my analysis software. I am new to both PostgreSQL and relational databases in general, and I have a very basic beginner's question: What software (e.g. pgAdmin III) and what and commands would I use to quickly answer the following questions on each machine:
Is PostgreSQL in still installed and running on each machine?
(If 1 is yes) Does the machine in question have installed any non-bundled tables or data?
(If 2 is yes) How can I produce a summary description of the tables that are installed?
In terms of a summary description, I am hoping for the table name, a list of column names, the data type of each, and the number of lines or records in each table, and possibly any additional database-relevant facts like whether the column is a key or indexed.
I work mainly under Windows 7 & 8, though I have a virtual Ubuntu macine installed on one computer.
Is postgreSQL in still installed and running on each machine?
The method you would use to find that out will depend on the operating system on each machine.
On Linux hosts you could use this:
ps -ef | grep postgres
If you see a process named postgres then postgresql is installed and running.
If not, it may be installed but not running. You could check the package management system of your distro to check if it is installed, for example on RPM based systems:
rpm -qa "*postgres*"
On a Windows machine you may be able to see if it is running using the task manager. To check if it is installed go into the Control Panel "Programs and Features" option.
Does the machine in question have installed any non-bundled tables or data?
By non-bundled I assume you mean tables or data other than the system catalogs that are created when you install the system.
My preference is to interact via the command line psql interface. Once you get the psql prompt you can use various 'backslash commands' to inspect the database.
To open the psql command - well you will need appropriate credentials. The details are going to depend on how you configured things when you installed it. If you happen to be using Linux, and you have root access, then the easiest way is to su to the postgres Linux user first, which in most cases will be able to connect directly to the database:
$ sudo su - postgres
$ psql
To see what databases exist use the \l command:
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+-------------+-------------+-----------------------
harmic | harmic | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 |
postgres | postgres | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 |
template0 | postgres | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_AU.UTF-8 | en_AU.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
(4 rows)
The databases postgres, template0 and template1 are created by the system so the only database containing user data is 'harmic' in this case.
To connect to a database use \c:
postgres=# \c harmic
You are now connected to database "harmic" as user "postgres".
To list all the tables that exist in this database, including system catalogs use \dt:
harmic=# \dt+ *.*
List of relations
Schema | Name | Type | Owner | Size | Description
--------------------+-------------------------+-------+----------+------------+-------------
information_schema | sql_features | table | postgres | 96 kB |
information_schema | sql_implementation_info | table | postgres | 48 kB |
information_schema | sql_languages | table | postgres | 48 kB |
information_schema | sql_packages | table | postgres | 48 kB |
information_schema | sql_parts | table | postgres | 48 kB |
information_schema | sql_sizing | table | postgres | 48 kB |
information_schema | sql_sizing_profiles | table | postgres | 8192 bytes |
pg_catalog | pg_aggregate | table | postgres | 40 kB |
pg_catalog | pg_am | table | postgres | 40 kB |
... etc
public | aaa | table | harmic | 16 kB |
public | entry | table | harmic | 8192 bytes |
public | exams | table | harmic | 8192 bytes |
(60 rows)
The tables listed in the Schema's 'information_schema' and 'pg_catalog' are not user tables. pg_catalog contains the internal information used by the database to keep track of everything in the database, and information_schema contains information tables about the database which are standardized by the SQL standard. In my case there are a few tables in the 'public' schema that are actual user tables.
How can I produce a summary description of the tables that are installed?
To see a full description of one or more tables:
harmic=# \d public.aaa
Table "public.aaa"
Column | Type | Modifiers
--------+---------+-----------
a | integer |
b | text |
The above trivial table has two columns named a and b, of types integer and text respectively.
You can use wildcards to get this listing printed for matching tables, eg:
harmic=# \d public.*
You can get an exact number of rows that exists in each table by executing:
SELECT count(1) FROM aaa;
(where aaa would be the table name).
Doing this for each and every table could be slow and tedious. You can get an approximation of the number of rows in all tables by inspecting some tables in the pg_catalog like this:
harmic=# SELECT nspname as schemaname,
harmic-# relname as tablename,
harmic-# reltuples as approx_rows
harmic-# FROM pg_class LEFT JOIN pg_namespace ON pg_namespace.oid=pg_class.relnamespace WHERE nspname='public' and relkind='r';
schemaname | tablename | approx_rows
------------+-----------+-------------
public | exams | 3
public | entry | 2
public | aaa | 2
(3 rows)
Note that the number of rows shown is updated whenever the database is analysed. The autovacuum daemon does this automatically from time to time, but you can also manually trigger it using command ANALYZE;
Question 1: What OS are you running? If its a sensible one(*nix), try running psql in the terminal of any of them. That will definitely tell you if psql is running. Whether postgres is installed is a totally different question. Determining that is very situation specific (What OS do you have?).
Question 2: Im not familiar with bundling tables. But simple inspection of the GUI provided by pgAdmin would be your best bet. What is bundling?
Question 3: Best way to generate a summary of a series of tables would be to run raw sql :)
The following will answer most of your described needs. Connect to psql and run something like the following:
connect <database_name>
\d (will list all the tables in the database)
\d <tablename> ('describes' the table)
select count(*) from <tablename> (returns the total number of rows in the table.)
This is the best place for postgres stuff: http://www.postgresql.org/docs/
Bloody boring reading, but very simple and to the point.
Best of luck!