Backing Up mysql db from the command line - command-line

I am trying to backup my database and keep getting error :
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '$ mysqldump -u root -p chandlers > backup_db.sql' at line 1
I am using the following command to launch the backup :
$ mysqldump -h localhost -u root -p chandlers > backup_db.sql
edit>>>>
This is how I connect to the db, this is a shortcut I have setup to open a command line :
C:\server2go\server2go\server\mysql\bin\mysql.exe -h localhost -P 7188 -u root
This works fine and connects, I have tried creating another like this >>
C:\server2go\server2go\server\mysql\bin\mysqldump.exe $ mysqldump -h localhost -P 7188 -u root -pchandlers > backup_db.sql
but I am getting an access denied error now.


you can use mysqldump to backup mysql database.
Below is the script example to backup mysql database in command line:-
$ mysqldump -h localhost -u username -p database_name > backup_db.sql
If your mysql database is very big, you might want to compress your sql file.
Just use the mysql backup command below and pipe the output to gzip,
then you will get the output as gzip file.
$ mysqldump -u username -h localhost -p database_name | gzip -9 > backup_db.sql.gz
If you want to extract the .gz file, use the command below:-
$ gunzip backup_db.sql.gz


You seem to be calling mysqldump from within mySQL, which is incorrect - it's a separate executable.
Call it from the command line instead.


I think it should be $ mysqldump -h localhost -u root -pchandlers > backup_db.sql. Otherwise it seems fine to me.

Related

Postgres How to execute SQL statement from command line [duplicate]

I have some .sql files with thousands of INSERT statements in them and need to run these inserts on my PostgreSQL database in order to add them to a table. The files are that large that it is impossible to open them and copy the INSERT statements into an editor window and run them there. I found on the Internet that you can use the following by navigating to the bin folder of your PostgreSQL install:
psql -d myDataBase -a -f myInsertFile
In my case:
psql -d HIGHWAYS -a -f CLUSTER_1000M.sql
I am then asked for a password for my user, but I cannot enter anything and when I hit enter I get this error:
psql: FATAL: password authentication failed for user "myUsername"
Why won't it let me enter a password. Is there a way round this as it is critical that I can run these scripts?
I got around this issue by adding a new entry in my pg_hba.conf file with the following structure:
# IPv6 local connections:
host myDbName myUserName ::1/128 trust
The pg_hba.conf file can usually be found in the 'data' folder of your PostgreSQL install.

Of course, you will get a fatal error for authenticating, because you do not include a user name...
Try this one, it is OK for me :)
psql -U username -d myDataBase -a -f myInsertFile
If the database is remote, use the same command with host
psql -h host -U username -d myDataBase -a -f myInsertFile

You should do it like this:
\i path_to_sql_file
See:

You have four choices to supply a password:
Set the PGPASSWORD environment variable. For details see the manual: http://www.postgresql.org/docs/current/static/libpq-envars.html
Use a .pgpass file to store the password. For details see the manual: http://www.postgresql.org/docs/current/static/libpq-pgpass.html
Use "trust authentication" for that specific user: http://www.postgresql.org/docs/current/static/auth-methods.html#AUTH-TRUST
Since PostgreSQL 9.1 you can also use a connection string: https://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING

Use this to execute *.sql files when the PostgreSQL server is located in a difference place:
psql -h localhost -d userstoreis -U admin -p 5432 -a -q -f /home/jobs/Desktop/resources/postgresql.sql
-h PostgreSQL server IP address
-d database name
-U user name
-p port which PostgreSQL server is listening on
-f path to SQL script
-a all echo
-q quiet
Then you are prompted to enter the password of the user.
EDIT: updated based on the comment provided by #zwacky

If you are logged in into psql on the Linux shell the command is:
\i fileName.sql
for an absolute path and
\ir filename.sql
for the relative path from where you have called psql.

export PGPASSWORD=<password>
psql -h <host> -d <database> -U <user_name> -p <port> -a -w -f <file>.sql

Via the terminal log on to your database and try this:
database-# >#pathof_mysqlfile.sql
or
database-#>-i pathof_mysqlfile.sql
or
database-#>-c pathof_mysqlfile.sql

You can give both user name and PASSSWORD on the command line itself with the "-d" parameter
psql -d "dbname='urDbName' user='yourUserName' password='yourPasswd' host='yourHost'" -f yourFileName.sql

you could even do it in this way:
sudo -u postgres psql -d myDataBase -a -f myInsertFile
If you have sudo access on machine and it's not recommended for production scripts just for test on your own machine it's the easiest way.

2021 Solution
if your PostgreSQL database is on your system locally.
psql dbname < sqldump.sql username
If its hosted online
psql -h hostname dbname < sqldump.sql username
If you have any doubts or questions, please ask them in the comments.

Walk through on how to run an SQL on the command line for PostgreSQL in Linux:
Open a terminal and make sure you can run the psql command:
psql --version
which psql
Mine is version 9.1.6 located in /bin/psql.
Create a plain textfile called mysqlfile.sql
Edit that file, put a single line in there:
select * from mytable;
Run this command on commandline (substituting your username and the name of your database for pgadmin and kurz_prod):
psql -U pgadmin -d kurz_prod -a -f mysqlfile.sql
The following is the result I get on the terminal (I am not prompted for a password):
select * from mytable;
test1
--------
hi
me too
(2 rows)

psql -h localhost -d userstoreis -U admin -p 5432 -a -q -f /home/jobs/Desktop/resources/postgresql.sql
Parameter explanations:
-h PostgreSQL server IP address
-d database name
-U user name
-p port which PostgreSQL server is listening on
-f path to SQL script
-a all echo
-q quiet

You can open a command prompt and run as administrator. Then type
../bin>psql -f c:/...-h localhost -p 5432 -d databasename -U "postgres"
Password for user postgres: will show up.
Type your password and enter. I couldn't see the password what I was typing, but this time when I press enter it worked. Actually I was loading data into the database.

I achived that wrote (located in the directory where my script is)
::someguy#host::$sudo -u user psql -d my_database -a -f file.sql
where -u user is the role who owns the database where I want to execute the script then the psql connects to the psql console after that -d my_database loads me in mydatabase finally -a -f file.sql where -a echo all input from the script and -f execute commands from file.sql into mydatabase, then exit.
I'm using:
psql (PostgreSQL) 10.12
on (Ubuntu 10.12-0ubuntu0.18.04.1)

A small improvement in #wingman__7 's 2021 answer: if your username contains certain characters (an underscore in my case), you need to pass it with the -U flag.
This worked for me:
$ psql -h db.host -d db_name -U my_user < query.sql

Try using the following command in the command line console:
psql -h localhost -U postgres -f restore.sql

how to restore a postgresql database from a file? [duplicate]

Locally, I use pgadmin3. On the remote server, however, I have no such luxury.
I've already created the backup of the database and copied it over, but is there a way to restore a backup from the command line? I only see things related to GUI or to pg_dumps.

There are two tools to look at, depending on how you created the dump file.
Your first source of reference should be the man page pg_dump as that is what creates the dump itself. It says:
Dumps can be output in script or
archive file formats. Script dumps are
plain-text files containing the SQL
commands required to reconstruct
the database to the state it was
in at the time it was saved. To
restore from such a script, feed it to
psql(1). Script files can be used
to reconstruct the database even
on other machines and other
architectures; with some modifications
even on other SQL database products.
The alternative archive file formats
must be used with pg_restore(1) to
rebuild the database. They allow
pg_restore to be selective about what
is restored, or even to reorder the
items prior to being restored. The
archive file formats are designed to
be portable across architectures.
So depends on the way it was dumped out. If using Linux/Unix, you can probably figure it out using the excellent file(1) command - if it mentions ASCII text and/or SQL, it should be restored with psql otherwise you should probably use pg_restore.
Restoring is pretty easy:
psql -U username -d dbname < filename.sql
-- For Postgres versions 9.0 or earlier
psql -U username -d dbname -1 -f filename.sql
or
pg_restore -U username -d dbname -1 filename.dump
Check out their respective manpages - there's quite a few options that affect how the restore works. You may have to clean out your "live" databases or recreate them from template0 (as pointed out in a comment) before restoring, depending on how the dumps were generated.

create backup
pg_dump -h localhost -p 5432 -U postgres -F c -b -v -f
"/usr/local/backup/10.70.0.61.backup" old_db
-F c is custom format (compressed, and able to do in parallel with -j N) -b is including blobs, -v is verbose, -f is the backup file name.
restore from backup
pg_restore -h localhost -p 5432 -U postgres -d old_db -v
"/usr/local/backup/10.70.0.61.backup"
important to set -h localhost - option

You might need to be logged in as postgres in order to have full privileges on databases.
su - postgres
psql -l # will list all databases on Postgres cluster
pg_dump/pg_restore
pg_dump -U username -f backup.dump database_name -Fc
switch -F specify format of backup file:
c will use custom PostgreSQL format which is compressed and results in smallest backup file size
d for directory where each file is one table
t for TAR archive (bigger than custom format)
-h/--host Specifies the host name of the machine on which the server is running
-W/--password Force pg_dump to prompt for a password before connecting to a database
restore backup:
pg_restore -d database_name -U username -C backup.dump
Parameter -C should create database before importing data. If it doesn't work you can always create database eg. with command (as user postgres or other account that has rights to create databases) createdb db_name -O owner
pg_dump/psql
In case that you didn't specify the argument -F default plain text SQL format was used (or with -F p). Then you can't use pg_restore. You can import data with psql.
backup:
pg_dump -U username -f backup.sql database_name
restore:
psql -d database_name -f backup.sql

POSTGRESQL 9.1.12
DUMP:
pg_dump -U user db_name > archive_name.sql
put the user password and press enter.
RESTORE:
psql -U user db_name < /directory/archive.sql
put the user password and press enter.

Below is my version of pg_dump which I use to restore the database:
pg_restore -h localhost -p 5432 -U postgres -d my_new_database my_old_database.backup
or use psql:
psql -h localhost -U postgres -p 5432 my_new_database < my_old_database.backup
where -h host, -p port, -u login username, -d name of database

Backup and restore with GZIP
For larger size database this is very good
backup
pg_dump -U user -d mydb | gzip > mydb.pgsql.gz
restore
gunzip -c mydb.pgsql.gz | psql dbname -U user
https://www.postgresql.org/docs/14/backup-dump.html

This worked for me:
pg_restore --verbose --clean --no-acl --no-owner --host=localhost --dbname=db_name --username=username latest.dump

Backup: $ pg_dump -U {user-name} {source_db} -f {dumpfilename.sql}
Restore: $ psql -U {user-name} -d {desintation_db} -f {dumpfilename.sql}

try this:
psql -U <username> -d <dbname> -f <filename>.sql
Restore DB psql from .sql file

Backup & Restore
This is the combo I'm using to backup, drop, create and restore my database (on macOS and Linux):
sudo -u postgres pg_dump -Fc mydb > ./mydb.sql
sudo -u postgres dropdb mydb
sudo -u postgres createdb -O db_user mydb
sudo -u postgres pg_restore -d mydb < ./mydb.sql
Misc
-Fc will compress the database (Format custom)
List PostgreSQL users: sudo -u postgres psql -c "\du+"
You may want to add hostname and date to ./mydb.sql, then change it by:
./`hostname`_mydb_`date +"%Y%m%d_%H%M"`.sql

If you create a backup using pg_dump you can easily restore it in the following way:
Open command line window
Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\9.5\bin"
Enter the command to restore your database. For example: psql.exe -U postgres -d YourDatabase -f D:\Backup\.sql
Type password for your postgres user
Check the restore process

I didnt see here mentions about dump file extension (*.dump).
This solution worked for me:
I got a dump file and needed to recover it.
First I tried to do this with pg_restore and got:
pg_restore: error: input file appears to be a text format dump. Please use psql.
I did it with psql and worked well:
psql -U myUser -d myDataBase < path_to_the_file/file.dump

1. Open the Terminal.
2. Backup your database with following command
your postgres bin -> /opt/PostgreSQL/9.1/bin/
your source database server -> 192.168.1.111
your backup file location and name -> /home/dinesh/db/mydb.backup
your source db name -> mydatabase
/opt/PostgreSQL/9.1/bin/pg_dump --host '192.168.1.111' --port 5432 --username "postgres" --no-password --format custom --blobs --file "/home/dinesh/db/mydb.backup" "mydatabase"
3. Restore mydb.backup file into destination.
your destination server -> localhost
your destination database name -> mydatabase
Create database for restore the backup.
/opt/PostgreSQL/9.1/bin/psql -h 'localhost' -p 5432 -U postgres -c "CREATE DATABASE mydatabase"
Restore the backup.
/opt/PostgreSQL/9.1/bin/pg_restore --host 'localhost' --port 5432 --username "postgres" --dbname "mydatabase" --no-password --clean "/home/dinesh/db/mydb.backup"

1) Open psql terminal.
2) Unzip/ untar the dump file.
3) Create an empty database.
4) use the following command to restore the .dump file
<database_name>-# \i <path_to_.dump_file>

To restore a dump file
psql -d [Dbname] -U [UserName] -p 5432 < [FileLocation]
To restore a .SQL file
pg_restore -U [Username] -d [Dbname] -1 [FileLocation]
If you get user authentication errors, go to the file pg_hba.conf which is in PSQL/data folder in your program files, and change the "METHOD" to "Trust".
Restart you psql serive in windows services(Win + R --> services.msc).

try:
pg_restore -h localhost -p 5432 -U <username> -d <dbname> -1 <filename>

Restoring a postgres backup file depends on how did you take the backup in the first place.
If you used pg_dump with -F c or -F d you need to use pg_restore otherwise you can just use
psql -h localhost -p 5432 -U postgres < backupfile
9 ways to backup and restore postgres databases

As below link said, you can use psql command for restoring the dump file:
https://www.postgresql.org/docs/8.1/static/backup.html#BACKUP-DUMP-RESTORE
psql dbname < infile
if you need to set username just add the username after the command like:
psql dbname < infile username

Sorry for the necropost, but these solutions did not work for me. I'm on postgres 10. On Linux:
I had to change directory to my pg_hba.conf.
I had to edit the file to change method from peer to md5 as stated here
Restart the service: service postgresql-10 restart
Change directory to where my backup.sql was located and execute:
psql postgres -d database_name -1 -f backup.sql
-database_name is the name of my database
-backup.sql is the name of my .sql backup file.

Try to see if the following commands can help you:
sudo su - yourdbuser
psql
\i yourbackupfile

If you have a backup SQL file then you can easily Restore it.
Just follow the instructions, given in the below
1. At first, create a database using pgAdmin or whatever you want (for example my_db is our created db name)
2. Now Open command line window
3. Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\pg10\bin"
4. Enter the following command to restore your database: psql.exe -U postgres -d my_db -f D:\Backup\backup_file_name.sql
Type password for your postgres user if needed and let Postgres to do its work. Then you can check the restore process.

The shortest way with no password prompt
psql "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"
If you are using Windows OS
psql.exe "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"

I was having authentication problems running pg_dump, so I moved my dump file
mv database_dump /tmp
into the temp directory and then ran
su -u postgres
cd /tmp
pg_restore database_dump
If you have a large database dump, you may just want to create another directory where your current user and the postgres user can access and putting the database dump file into that.

Backup==>
Option1: To take backup along with password in cmd
1.PGPASSWORD="mypassword" pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option2: To take backup without password in cmd
2. pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option3: To take backup as gzip(if database is huge)
3. pg_dump -U postgres -h localhost mydb --inserts | gzip > mydb.gz
Restore:
1. psql -h localhost -d mydb -U postgres -p 5432 < mydb.sql

This solution only works for Windows.
First, ensure you have already added the postgres bin folder to the "Path" environment variable (in my case this folder is C:\Program Files\PostgreSQL\12\bin).
Then, open the Windows command interpreter (cmd), go to the folder where you have the .sql file and execute this command:
pg_restore -U userName -d database-1 backupfile.sql
For example:
pg_restore -U sam -d SamDataBase -1 SamDataBaseBackup.sql
(It can ask you for the password of the user so ensure to type it correctly and then click enter)
Pura vida!

If you have created a new database named mydb, To restore a .sql dump to that database with psql,
psql --file=dump.sql --username=postgres --host=localhost --port=5432 mydb
the password will be prompted by psql
The connection options are
-h, --host=HOSTNAME database server host or socket directory (default: "/var/run/postgresql")
-p, --port=PORT database server port (default: "5432")
-U, --username=USERNAME database user name (default: "xyz")
-w, --no-password never prompt for password
-W, --password force password prompt (should happen automatically)

If you are using docker, this answer may be helpful.
Start the container
docker start <postgres_container_id>
Access bash inside container
docker exec -it <postgres_container_id> bash
Copy the .tar backup file to docker container (In another window)
docker cp postgres_dump.tar <postgres_container_id>:/
Restore the backup
pg_restore -c -U <postgres-user> -d <password> -v "postgres_dump.tar" -W
Enter password

Save and restore the exact same state with compressed dump
Other answers gave all the key bits separately, but hopefully this will provide be the "just works save and restore to exact state" command pair.
Dump to file mydb.psql:
PGPASSWORD=mypassword pg_dump -U my_username -h localhost mydb -Fc -f mydb.psql
Restore:
PGPASSWORD=mypassword pg_restore -U my_username -h localhost \
--clean -d mydb -v mydb.psql
Some of the flags:
-Fc: Format Compressed, as opposed to plaintext.
file tmp.psql says:
tmp.psql: PostgreSQL custom database dump - v1.14-0
--clean: destroy the target DB before restoring it, thus returning to the exact same pristine state.
Any data created after the dump will be lost.
PGPASSWORD, -U and -h can of course be modified depending on your login method, e.g. without PGPASSWORD you're prompted for a password, and none of those are needed if you set up peer auth locally.
Tested on Ubuntu 22.04, PostgreSQL 14.5.

If you want to backup your data or restore data from a backup, you can run the following commands:
To create backup of your data, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type the following command:
pg_dump -FC -U ngb -d ngb -p 5432 >C:\BACK_UP\ngb.090718_after_readUpload.backup
To restore data from a backup, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type below command:
C:\programFiles\postgres\10\bin> pg_restore -Fc -U ngb -d ngb -p 5432 <C:\ngb.130918.backup
Please make sure that the backup file exists.

Follow these 3 steps :
start postgres server - sudo systemctl start postgresql
enable same - sudo systemctl enable postgresql
restore command - pg_restore -h localhost -p 5432 -U postgres -d old_db
assuming that the dump is there in the same directory
Links :
https://www.postgresqltutorial.com/postgresql-restore-database
https://askubuntu.com/questions/50621/cannot-connect-to-postgresql-on-port-5432

postgresql dump - unable to use it to create a new database on a new server

I've run the following command on an existing database server:
pg_dump -C -U testuser testdb -h 127.0.0.1 -F t> testdbdump
Now I'm trying to create this testdb on a new server.
I tried to run the following command on the new server:
pg_restore -h 127.0.0.1 testdbdump
I've created the testuser role on the new database server. And then I also tried the following:
pg_restore -i -h 127.0.0.1 -p 5432 -U postgres "testdbdump"
psql template1 postgres -f testdbdump
It did start to do some stuff, but I get a bunch of errors including:
psql:testdbdump:1720: invalid command \N
psql:testdbdump:1721: invalid command \N
psql:testdbdump:1808: ERROR: syntax error at or near "user"
LINE 1: user=phone
^
Did I create the dump file incorrectly?

Look up the --create option of pg_restore. It's made for this purpose.

Run a PostgreSQL .sql file using command line arguments

I have some .sql files with thousands of INSERT statements in them and need to run these inserts on my PostgreSQL database in order to add them to a table. The files are that large that it is impossible to open them and copy the INSERT statements into an editor window and run them there. I found on the Internet that you can use the following by navigating to the bin folder of your PostgreSQL install:
psql -d myDataBase -a -f myInsertFile
In my case:
psql -d HIGHWAYS -a -f CLUSTER_1000M.sql
I am then asked for a password for my user, but I cannot enter anything and when I hit enter I get this error:
psql: FATAL: password authentication failed for user "myUsername"
Why won't it let me enter a password. Is there a way round this as it is critical that I can run these scripts?
I got around this issue by adding a new entry in my pg_hba.conf file with the following structure:
# IPv6 local connections:
host myDbName myUserName ::1/128 trust
The pg_hba.conf file can usually be found in the 'data' folder of your PostgreSQL install.

Of course, you will get a fatal error for authenticating, because you do not include a user name...
Try this one, it is OK for me :)
psql -U username -d myDataBase -a -f myInsertFile
If the database is remote, use the same command with host
psql -h host -U username -d myDataBase -a -f myInsertFile

You should do it like this:
\i path_to_sql_file
See:

You have four choices to supply a password:
Set the PGPASSWORD environment variable. For details see the manual: http://www.postgresql.org/docs/current/static/libpq-envars.html
Use a .pgpass file to store the password. For details see the manual: http://www.postgresql.org/docs/current/static/libpq-pgpass.html
Use "trust authentication" for that specific user: http://www.postgresql.org/docs/current/static/auth-methods.html#AUTH-TRUST
Since PostgreSQL 9.1 you can also use a connection string: https://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING

Use this to execute *.sql files when the PostgreSQL server is located in a difference place:
psql -h localhost -d userstoreis -U admin -p 5432 -a -q -f /home/jobs/Desktop/resources/postgresql.sql
-h PostgreSQL server IP address
-d database name
-U user name
-p port which PostgreSQL server is listening on
-f path to SQL script
-a all echo
-q quiet
Then you are prompted to enter the password of the user.
EDIT: updated based on the comment provided by #zwacky

If you are logged in into psql on the Linux shell the command is:
\i fileName.sql
for an absolute path and
\ir filename.sql
for the relative path from where you have called psql.

export PGPASSWORD=<password>
psql -h <host> -d <database> -U <user_name> -p <port> -a -w -f <file>.sql

Via the terminal log on to your database and try this:
database-# >#pathof_mysqlfile.sql
or
database-#>-i pathof_mysqlfile.sql
or
database-#>-c pathof_mysqlfile.sql

You can give both user name and PASSSWORD on the command line itself with the "-d" parameter
psql -d "dbname='urDbName' user='yourUserName' password='yourPasswd' host='yourHost'" -f yourFileName.sql

you could even do it in this way:
sudo -u postgres psql -d myDataBase -a -f myInsertFile
If you have sudo access on machine and it's not recommended for production scripts just for test on your own machine it's the easiest way.

2021 Solution
if your PostgreSQL database is on your system locally.
psql dbname < sqldump.sql username
If its hosted online
psql -h hostname dbname < sqldump.sql username
If you have any doubts or questions, please ask them in the comments.

Walk through on how to run an SQL on the command line for PostgreSQL in Linux:
Open a terminal and make sure you can run the psql command:
psql --version
which psql
Mine is version 9.1.6 located in /bin/psql.
Create a plain textfile called mysqlfile.sql
Edit that file, put a single line in there:
select * from mytable;
Run this command on commandline (substituting your username and the name of your database for pgadmin and kurz_prod):
psql -U pgadmin -d kurz_prod -a -f mysqlfile.sql
The following is the result I get on the terminal (I am not prompted for a password):
select * from mytable;
test1
--------
hi
me too
(2 rows)

psql -h localhost -d userstoreis -U admin -p 5432 -a -q -f /home/jobs/Desktop/resources/postgresql.sql
Parameter explanations:
-h PostgreSQL server IP address
-d database name
-U user name
-p port which PostgreSQL server is listening on
-f path to SQL script
-a all echo
-q quiet

You can open a command prompt and run as administrator. Then type
../bin>psql -f c:/...-h localhost -p 5432 -d databasename -U "postgres"
Password for user postgres: will show up.
Type your password and enter. I couldn't see the password what I was typing, but this time when I press enter it worked. Actually I was loading data into the database.

I achived that wrote (located in the directory where my script is)
::someguy#host::$sudo -u user psql -d my_database -a -f file.sql
where -u user is the role who owns the database where I want to execute the script then the psql connects to the psql console after that -d my_database loads me in mydatabase finally -a -f file.sql where -a echo all input from the script and -f execute commands from file.sql into mydatabase, then exit.
I'm using:
psql (PostgreSQL) 10.12
on (Ubuntu 10.12-0ubuntu0.18.04.1)

A small improvement in #wingman__7 's 2021 answer: if your username contains certain characters (an underscore in my case), you need to pass it with the -U flag.
This worked for me:
$ psql -h db.host -d db_name -U my_user < query.sql

Try using the following command in the command line console:
psql -h localhost -U postgres -f restore.sql

Restore a postgres backup file using the command line?

Locally, I use pgadmin3. On the remote server, however, I have no such luxury.
I've already created the backup of the database and copied it over, but is there a way to restore a backup from the command line? I only see things related to GUI or to pg_dumps.

There are two tools to look at, depending on how you created the dump file.
Your first source of reference should be the man page pg_dump as that is what creates the dump itself. It says:
Dumps can be output in script or
archive file formats. Script dumps are
plain-text files containing the SQL
commands required to reconstruct
the database to the state it was
in at the time it was saved. To
restore from such a script, feed it to
psql(1). Script files can be used
to reconstruct the database even
on other machines and other
architectures; with some modifications
even on other SQL database products.
The alternative archive file formats
must be used with pg_restore(1) to
rebuild the database. They allow
pg_restore to be selective about what
is restored, or even to reorder the
items prior to being restored. The
archive file formats are designed to
be portable across architectures.
So depends on the way it was dumped out. If using Linux/Unix, you can probably figure it out using the excellent file(1) command - if it mentions ASCII text and/or SQL, it should be restored with psql otherwise you should probably use pg_restore.
Restoring is pretty easy:
psql -U username -d dbname < filename.sql
-- For Postgres versions 9.0 or earlier
psql -U username -d dbname -1 -f filename.sql
or
pg_restore -U username -d dbname -1 filename.dump
Check out their respective manpages - there's quite a few options that affect how the restore works. You may have to clean out your "live" databases or recreate them from template0 (as pointed out in a comment) before restoring, depending on how the dumps were generated.

create backup
pg_dump -h localhost -p 5432 -U postgres -F c -b -v -f
"/usr/local/backup/10.70.0.61.backup" old_db
-F c is custom format (compressed, and able to do in parallel with -j N) -b is including blobs, -v is verbose, -f is the backup file name.
restore from backup
pg_restore -h localhost -p 5432 -U postgres -d old_db -v
"/usr/local/backup/10.70.0.61.backup"
important to set -h localhost - option

You might need to be logged in as postgres in order to have full privileges on databases.
su - postgres
psql -l # will list all databases on Postgres cluster
pg_dump/pg_restore
pg_dump -U username -f backup.dump database_name -Fc
switch -F specify format of backup file:
c will use custom PostgreSQL format which is compressed and results in smallest backup file size
d for directory where each file is one table
t for TAR archive (bigger than custom format)
-h/--host Specifies the host name of the machine on which the server is running
-W/--password Force pg_dump to prompt for a password before connecting to a database
restore backup:
pg_restore -d database_name -U username -C backup.dump
Parameter -C should create database before importing data. If it doesn't work you can always create database eg. with command (as user postgres or other account that has rights to create databases) createdb db_name -O owner
pg_dump/psql
In case that you didn't specify the argument -F default plain text SQL format was used (or with -F p). Then you can't use pg_restore. You can import data with psql.
backup:
pg_dump -U username -f backup.sql database_name
restore:
psql -d database_name -f backup.sql

POSTGRESQL 9.1.12
DUMP:
pg_dump -U user db_name > archive_name.sql
put the user password and press enter.
RESTORE:
psql -U user db_name < /directory/archive.sql
put the user password and press enter.

Below is my version of pg_dump which I use to restore the database:
pg_restore -h localhost -p 5432 -U postgres -d my_new_database my_old_database.backup
or use psql:
psql -h localhost -U postgres -p 5432 my_new_database < my_old_database.backup
where -h host, -p port, -u login username, -d name of database

Backup and restore with GZIP
For larger size database this is very good
backup
pg_dump -U user -d mydb | gzip > mydb.pgsql.gz
restore
gunzip -c mydb.pgsql.gz | psql dbname -U user
https://www.postgresql.org/docs/14/backup-dump.html

This worked for me:
pg_restore --verbose --clean --no-acl --no-owner --host=localhost --dbname=db_name --username=username latest.dump

Backup: $ pg_dump -U {user-name} {source_db} -f {dumpfilename.sql}
Restore: $ psql -U {user-name} -d {desintation_db} -f {dumpfilename.sql}

try this:
psql -U <username> -d <dbname> -f <filename>.sql
Restore DB psql from .sql file

Backup & Restore
This is the combo I'm using to backup, drop, create and restore my database (on macOS and Linux):
sudo -u postgres pg_dump -Fc mydb > ./mydb.sql
sudo -u postgres dropdb mydb
sudo -u postgres createdb -O db_user mydb
sudo -u postgres pg_restore -d mydb < ./mydb.sql
Misc
-Fc will compress the database (Format custom)
List PostgreSQL users: sudo -u postgres psql -c "\du+"
You may want to add hostname and date to ./mydb.sql, then change it by:
./`hostname`_mydb_`date +"%Y%m%d_%H%M"`.sql

If you create a backup using pg_dump you can easily restore it in the following way:
Open command line window
Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\9.5\bin"
Enter the command to restore your database. For example: psql.exe -U postgres -d YourDatabase -f D:\Backup\.sql
Type password for your postgres user
Check the restore process

I didnt see here mentions about dump file extension (*.dump).
This solution worked for me:
I got a dump file and needed to recover it.
First I tried to do this with pg_restore and got:
pg_restore: error: input file appears to be a text format dump. Please use psql.
I did it with psql and worked well:
psql -U myUser -d myDataBase < path_to_the_file/file.dump

1. Open the Terminal.
2. Backup your database with following command
your postgres bin -> /opt/PostgreSQL/9.1/bin/
your source database server -> 192.168.1.111
your backup file location and name -> /home/dinesh/db/mydb.backup
your source db name -> mydatabase
/opt/PostgreSQL/9.1/bin/pg_dump --host '192.168.1.111' --port 5432 --username "postgres" --no-password --format custom --blobs --file "/home/dinesh/db/mydb.backup" "mydatabase"
3. Restore mydb.backup file into destination.
your destination server -> localhost
your destination database name -> mydatabase
Create database for restore the backup.
/opt/PostgreSQL/9.1/bin/psql -h 'localhost' -p 5432 -U postgres -c "CREATE DATABASE mydatabase"
Restore the backup.
/opt/PostgreSQL/9.1/bin/pg_restore --host 'localhost' --port 5432 --username "postgres" --dbname "mydatabase" --no-password --clean "/home/dinesh/db/mydb.backup"

1) Open psql terminal.
2) Unzip/ untar the dump file.
3) Create an empty database.
4) use the following command to restore the .dump file
<database_name>-# \i <path_to_.dump_file>

To restore a dump file
psql -d [Dbname] -U [UserName] -p 5432 < [FileLocation]
To restore a .SQL file
pg_restore -U [Username] -d [Dbname] -1 [FileLocation]
If you get user authentication errors, go to the file pg_hba.conf which is in PSQL/data folder in your program files, and change the "METHOD" to "Trust".
Restart you psql serive in windows services(Win + R --> services.msc).

try:
pg_restore -h localhost -p 5432 -U <username> -d <dbname> -1 <filename>

Restoring a postgres backup file depends on how did you take the backup in the first place.
If you used pg_dump with -F c or -F d you need to use pg_restore otherwise you can just use
psql -h localhost -p 5432 -U postgres < backupfile
9 ways to backup and restore postgres databases

As below link said, you can use psql command for restoring the dump file:
https://www.postgresql.org/docs/8.1/static/backup.html#BACKUP-DUMP-RESTORE
psql dbname < infile
if you need to set username just add the username after the command like:
psql dbname < infile username

Sorry for the necropost, but these solutions did not work for me. I'm on postgres 10. On Linux:
I had to change directory to my pg_hba.conf.
I had to edit the file to change method from peer to md5 as stated here
Restart the service: service postgresql-10 restart
Change directory to where my backup.sql was located and execute:
psql postgres -d database_name -1 -f backup.sql
-database_name is the name of my database
-backup.sql is the name of my .sql backup file.

Try to see if the following commands can help you:
sudo su - yourdbuser
psql
\i yourbackupfile

If you have a backup SQL file then you can easily Restore it.
Just follow the instructions, given in the below
1. At first, create a database using pgAdmin or whatever you want (for example my_db is our created db name)
2. Now Open command line window
3. Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\pg10\bin"
4. Enter the following command to restore your database: psql.exe -U postgres -d my_db -f D:\Backup\backup_file_name.sql
Type password for your postgres user if needed and let Postgres to do its work. Then you can check the restore process.

The shortest way with no password prompt
psql "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"
If you are using Windows OS
psql.exe "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"

I was having authentication problems running pg_dump, so I moved my dump file
mv database_dump /tmp
into the temp directory and then ran
su -u postgres
cd /tmp
pg_restore database_dump
If you have a large database dump, you may just want to create another directory where your current user and the postgres user can access and putting the database dump file into that.

Backup==>
Option1: To take backup along with password in cmd
1.PGPASSWORD="mypassword" pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option2: To take backup without password in cmd
2. pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option3: To take backup as gzip(if database is huge)
3. pg_dump -U postgres -h localhost mydb --inserts | gzip > mydb.gz
Restore:
1. psql -h localhost -d mydb -U postgres -p 5432 < mydb.sql

This solution only works for Windows.
First, ensure you have already added the postgres bin folder to the "Path" environment variable (in my case this folder is C:\Program Files\PostgreSQL\12\bin).
Then, open the Windows command interpreter (cmd), go to the folder where you have the .sql file and execute this command:
pg_restore -U userName -d database-1 backupfile.sql
For example:
pg_restore -U sam -d SamDataBase -1 SamDataBaseBackup.sql
(It can ask you for the password of the user so ensure to type it correctly and then click enter)
Pura vida!

If you have created a new database named mydb, To restore a .sql dump to that database with psql,
psql --file=dump.sql --username=postgres --host=localhost --port=5432 mydb
the password will be prompted by psql
The connection options are
-h, --host=HOSTNAME database server host or socket directory (default: "/var/run/postgresql")
-p, --port=PORT database server port (default: "5432")
-U, --username=USERNAME database user name (default: "xyz")
-w, --no-password never prompt for password
-W, --password force password prompt (should happen automatically)

If you are using docker, this answer may be helpful.
Start the container
docker start <postgres_container_id>
Access bash inside container
docker exec -it <postgres_container_id> bash
Copy the .tar backup file to docker container (In another window)
docker cp postgres_dump.tar <postgres_container_id>:/
Restore the backup
pg_restore -c -U <postgres-user> -d <password> -v "postgres_dump.tar" -W
Enter password

Save and restore the exact same state with compressed dump
Other answers gave all the key bits separately, but hopefully this will provide be the "just works save and restore to exact state" command pair.
Dump to file mydb.psql:
PGPASSWORD=mypassword pg_dump -U my_username -h localhost mydb -Fc -f mydb.psql
Restore:
PGPASSWORD=mypassword pg_restore -U my_username -h localhost \
--clean -d mydb -v mydb.psql
Some of the flags:
-Fc: Format Compressed, as opposed to plaintext.
file tmp.psql says:
tmp.psql: PostgreSQL custom database dump - v1.14-0
--clean: destroy the target DB before restoring it, thus returning to the exact same pristine state.
Any data created after the dump will be lost.
PGPASSWORD, -U and -h can of course be modified depending on your login method, e.g. without PGPASSWORD you're prompted for a password, and none of those are needed if you set up peer auth locally.
Tested on Ubuntu 22.04, PostgreSQL 14.5.

If you want to backup your data or restore data from a backup, you can run the following commands:
To create backup of your data, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type the following command:
pg_dump -FC -U ngb -d ngb -p 5432 >C:\BACK_UP\ngb.090718_after_readUpload.backup
To restore data from a backup, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type below command:
C:\programFiles\postgres\10\bin> pg_restore -Fc -U ngb -d ngb -p 5432 <C:\ngb.130918.backup
Please make sure that the backup file exists.

Follow these 3 steps :
start postgres server - sudo systemctl start postgresql
enable same - sudo systemctl enable postgresql
restore command - pg_restore -h localhost -p 5432 -U postgres -d old_db
assuming that the dump is there in the same directory
Links :
https://www.postgresqltutorial.com/postgresql-restore-database
https://askubuntu.com/questions/50621/cannot-connect-to-postgresql-on-port-5432