I'm experienced with MySQL, but I've just started to work with Postgres - from the terminal on my Mac, how can I see the list of existing Postgres databases using the psql command?
I checked the documentation and I've seen this issue brought up here - https://dba.stackexchange.com/questions/1285/how-do-i-list-all-databases-and-tables-using-psql, where the accepted solution is to simply type psql \l, and that makes sense to me... however, when I try this, I get the error
psql: FATAL: database "l" does not exist
but I am logged in to Postgres - if I type psql DATABASE_NAME, no problem, I get into the database... this was an issue for me recently because I couldn't remember the name of the database that I wanted to work on. I went into another table (the name of which I did remember), then used the \l command to see my databases and connected to the DB I needed, but I'd much rather just be able to see a list without having to first connect to a database. How can I do that?
Thanks to #Michał Sznurawa for pointing me in the right direction - from the Mac terminal, using psql -l, rather than psql \l does the trick.
Related
I am a new user of PostgreSQL, and I am learning it so that I can use it with Django, so I am trying to use the createdb command to create a new database, but even though I am entering the correct password for my account, I am getting this error. I reinstalled everything and checked everything I could think of but I was not able to solve this error. So, if I can get some help regarding this issue it would be nice.
Even using the command psql, and submitting the correct password, gives the same error.
I am using Windows 10.
As far as I checked, I needed to enter the password I used while installing PostgreSQL.
By the way, I am using the latest version of PostgreSQL 14.1
The command I used:
createdb testdatabase
createdb: error: connection to server at "localhost" (::1), port 5432 failed:
FATAL: password authentication failed for user "<username_placeholder>"
So, basically, I figured the solution myself. I am just posting it here because mostly answers are available for Linux and not Windows. So, if a windows user has a similar problem, maybe this answer could help them.
So, the first thing is, if you need to open psql, use the command:
psql -U postgres
and then enter the password you used while installing PostgreSQL. Now, if you wish to do something similar to what I tried, what I mean is to use createdb command in the terminal itself, then you will have to create a new user using the same username as you do for your PC, like in my case, it is aryan.
(For example: C:\Users\aryan\).
I followed instructions from this website.
I personally used pgAdmin 4 to do it, you could also use the SQL commands themselves.
After doing everything, when I used the createdb command directly from the terminal/powershell, it asked my the password which I had used to create the other user( with the same username as my system/pc) using pgAdmin 4. That's it. This helped me out.
I need to understand the relations between tables in a PostgreSQL database. I will not have the ability to download pgAdmin4 like I am used to working in. So after looking around I found pg_dump.exe built into PostgreSQL. I thought I could just do something like this in the SQL Shell (psql) to get a dump of the database and then have the ability to upload it into another system:
database=# pg_dump database > path/to/save/file.sql;
Based on the docs >> https://www.postgresql.org/docs/9.3/app-pgdump.html
But when I run that I get an error:
ERROR: syntax error at or near "pg_dump"
LINE 1: pg_dump database > path/to/save/file.sql;
^
I saw on this stack overflow question was similar to my issue with the pg_dump error. In the solutions, Adrian says that pg_dump does not work within psql. When I run the code that Adrian suggested, I also get an error.
Any thoughts on how I can use psql to get the information that I need of this database?
Note: I am accessing a Linux VM on a Windows machine.
I need to copy a schema in Postgres to another database on a remote server, but I keep up ending to get a fail like:
pg_dump: too many command-line arguments (first is "--n")
My code:
pg_dump postgres -n my_local_shema | psql -h 11.22.33.44 -U my_user_on_remote_server-d postgres
I have tried for hours and with different commands but I keep getting the "too many command lines".
Try with a reversed order like this:
pg_dump -n my_local_shema postgres
Ok. This command structure works as a charm:
pg_dump -n my_local_shema_name -d my_local_database -U my_local_username | psql -h 111.222.333.444 -U my_user_name_on_remote_Server my_Database_name_on_remote_server
Step-by-step-guide
I copied a shema with all tables and indexes to another database on another server.
The 111.222.333.444 is the IP of the remote server.
In preparation(I dont know if it is actually needed), I first created a shema on the remote server with an identical shemaname as the one, I wanted to copy. I also checked, that the firewall was open for datatransfer from the old server to the new one.
Then, i opened a commandpromt (I use windows) and opened the folder where the pgdump.exefile was. Here typed the command.
Last it asked me to type in a password. First it promted it. THen it was silent - nothing happened, and I did not know, what to expect. Last I typed in the password 2 times (i use the same password both on the old server and the new, upgraded one). Then things started to work and it wrote a lot with alter table, ect, ect.
Hope others can use it. :-)
I have successfully logged in a PostgreSQL database with psql -d <name> -h <IP address> -U <user name>. However, commands like \d and queries like SELECT * FROM Table LIMIT 5; return nothing without errors, but only \copyright returns the paragraph. Even \? and \h give me nothing. I am pretty sure that this database is not empty because I can retrieve information with the same logins and queries with pandas.read_sql in Python and RPostgreSQL::dbGetQuery in R. Hence it should be problems in psql.
My wild guess is this might be a similar problem of pager when executing git diff as I just fixed that a few days ago. Is it possible? If so, how can I change the pager settings? If not, what can be reasons causing the situation and how to fix it?
The information of OS and PostgreSQL are listed below:
Ubuntu 14.04.5 LTS
psql (10.1, server 9.4.15)
First of all, I apologize if this question turns out to be painfully obvious, I'm not that postgres-savvy beyond the basics. I use postgresql as a database backend for quite a few django projects that I'm working on, and that's always worked just fine for me. Recently, I set up postgresql on a new machine, and at one point a co worker tried setting up a new project on that machine. Unfortunately, it's too late to go back into the bash history to figure out what he did, and he won't be available for a while to ask him about it. The issue i'm having now is...
I regularly reset postgres databases by simply using a dropdb/createdb command. I've noticed that whenever I run the dropdb command, the database does disappear, but when I run the createdb command next, the resulting database is not empty. It contains tables, and those tables do contain data (which appears to be dummy data from the other project). I realise that i'm a bit of a postgres noob, but is this in some way related to template features in postgres? I don't specify anything like that on the command line, and I'm seeing the exact same results if I drop/create from the psql console.
By the way, I can still wipe the db by dropping and recreating the "public" schema in the database. I'll be glad to add any info necessary to help figure this out, but to be honest I haven't a clue what to look for at this point. Any help would be much appreciated.
Summarizing from the docs template0 is essentially a clean, virgin system database, whereas template1 serves as a blue print for any new database created with the createdb command or create database from a psql prompt (there is no effective difference).
It is probable that you have some tables lurking in template1, which is why they keep reappearing on createdb. You can solve this by dropping template1 and recreating it from template0.
createdb -T template0 template1
The template1 database can be extremely useful. I use Postgis a lot, so I have all of the functions and tables related to that installed in template1, so any new database I create is immediately spatially enabled.
EDIT. As noted in docs, but worth emphasizing, to delete tempate1 you need to have pg_database.datistemplate = false set.