I'm developing a ruby app and want to delete my testing users in the SQL database is there a command line to delete them all. Like to start fresh through testing
You can do rails db:migrate:resetto delete everything and recreate your database
To delete database in rails using command lines run in this command in the rails app directory.
bundle exec rake db:drop:all
The above code will delete the entire database. Alternatively you can delete the database using mysql also by listing all the databases present and choosing the one to delete.
Open up terminal and type mysql -u yourusername -p, hit enter and type your root password.
show databases;
drop database yourdatabase;
Related
I am creating a Software configuration for MySQL 5.6.22 and I'll need to create the root administration user root:rootroot.
Next step, I'll need to install as service/daemon with auto-start option and finally this installation needs:
MySQL Workbench 6.2.4
MySQL Connector/J 5.1.34
To configure the Data Base on RNL Lab of the project the programmer shell do:
The mysql -uroot -p try to connect to the server and it won't have access to it.
The programmer shell always use mysql-local-client, this might work as an alias to the root, while the pass maintains the same as "root".
For running the project it must be started by the MySQL Server on the working Computer:
mysql-local-start
At the end it might encounter the running server port (should be the 10000 or 10001).
After that it must have a connection to the server, using other command line, to creating the user, give the right privilege and finally for creating the Data Base with:
mysql-local-client
It's necessary to use this command, that works as an alias for the last server created.
Please run the next commands on MySQL Shell from the mysql-local-client:
CREATE USER 'bubble'#'localhost' IDENTIFIED BY 'bubbl3';
CREATE USER 'bubble'#'%' IDENTIFIED BY 'bubbl3';
GRANT ALL PRIVILEGES ON bubbledb.* TO 'bubble'#'localhost';
GRANT ALL PRIVILEGES ON bubbledb.* TO 'bubble'#'%';
CREATE DATABASE bubbledb;
At last it needed to change the properties for the Fenix Framework so that the next code runs (where 10000 is the running server port):
dbAlias=//localhost:10000/bubbledb?useUnicode=true&characterEncoding=UTF-8&clobCharacterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull
dbUsername=bubble
dbPassword=bubbl3"
Unfortunately, I have removed super user privileges from postgres user in PostgreSQL. And currently I have not any super user in PostgreSQL. And i want to make superuser. So how can i make it ? Every time I am trying to make postgres to super user. I am facing this problem.
Error : must be superuser to alter superusers.
(assuming you have root access on Ubuntu machine)
To enter psql as super user you need to:
sudo -u postgres psql
as suggested in this SO post here
If there is no user called postgres you need to create it on system first, with:
sudo adduser newuser
Else, if you have problems with password not accepted or not created at all you can follow (Ubuntu 14.04 related) instructions here or for more on user accounts look here
For me helps:
sudo -u gleb psql postgres
where gleb is my mac system user
Adding to Craig Ringer's answer, here is the procedure for MacOS and Brew if you accidentally downgrade your only PostgreSQL user:
brew services stop postgresql
Wait a few seconds and/or check Activity Monitor to make sure "postgres" is no longer running.
/usr/local/Cellar/postgresql/10.4/bin/postgres --single -D /usr/local/var/postgres
backend> ALTER USER "yourname" with superuser; or whatever privilege you need to fix
CTRL-D
brew services start postgresql
You're going to have to stop the database system and start a stand-alone back-end, which always unconditionally runs as a superuser.
You can use this backend to ALTER the user you wish to give superuser rights to. Then shut the standalone backend down and start the database normally.
It is important that you completely stop the database server before entering single user mode. PostgreSQL single user mode will refuse to start if there's a postmaster, but to be sure you should make sure there are no PostgreSQL processes running on your system. Under (almost) no circumstances should you ever delete postmaster.pid - that's pretty much guaranteed to result in database corruption if there's still any PostgreSQL process accessing that data directory.
Exactly how to start a standalone back-end depends a bit on your OS/distro and how you installed PostgreSQL. You haven't included this info, so I can only really point you at the manual for the postgres back-end executable.
Make a backup first.
In the single-user mode, the session user will be set to the user with ID 1, and implicit superuser powers are granted to this user. This user does not actually have to exist, so the single-user mode can be used to manually recover from certain kinds of accidental damage to the system catalogs.
See the section Options for Single User mode and, toward the bottom, Usage. You'll want to run the postgres backend with --single, as the unix user that owns the database files, with the path to the datadir. On a typical Linux PostgreSQL install this might be something like:
sudo systemctl stop postgresql-9.3.service
sudo -u postgres /usr/pgsql-9.3/bin/postgres --single -D /var/lib/pgsql/9.3/data
Your datadir and postgres executable location are quite possibly different. The above is for a Fedora system running with PGDG PostgreSQL packages from http://yum.postgresql.org/ .
Assuming that your system user is 'ec2-user'
So try this to enter as superuser
psql -U ec2-user postgres
This will enter you as ec2-user as superuser using postgres db
Now, change postgres user roles to superuser
ALTER USER postgres WITH SUPERUSER;
Quit from above console and now you can open psql using postgres user as superuser
psql -U postgres
Note: I tested this on PostgreSQL 12.5
SELECT usename AS role_name,
CASE
WHEN usesuper AND usecreatedb THEN
CAST('superuser, create database' AS pg_catalog.text)
WHEN usesuper THEN
CAST('superuser' AS pg_catalog.text)
WHEN usecreatedb THEN
CAST('create database' AS pg_catalog.text)
ELSE
CAST('' AS pg_catalog.text)
END role_attributes
FROM pg_catalog.pg_user
ORDER BY role_name desc;
log with root_user then give superuser to postgres
Alright, so I've got a fairly fresh Ubuntu (server) installation. Just finished installing the LAMP server and when I go to create a database I'm getting the generic syntax error (1064 / 42000).
My query:
CREATE DATABASE phpbb;
Pretty simple and pretty standard, so I'm not sure what the issue is. Any ideas?
It looks from your error like you're trying to execute SQL on the command line, something like:
mysql -u mike -p CREATE DATABASE phpbb';
MySQL isn't going to like that, it separates the initiation of the tool from the SQL commands.
What I'd normally do for CREATE DATABASE, as it's a one off, I'd do it manually.
So start the tool with
mysql -u mike -p
This should prompt you for your password, and connect to the local database, giving you a shell prompt:
mysql>
You then issue your
CREATE DATABASE phpbb;
If you want to run scripts from the command line, put them in a file and redirect the input to mysql. Usually you'd redirect the output too - something like this:
mysql -u mike -p < mysqlscript.sql > outputofscript.log
I want to use mysql with a rails app (I have never used mysql before). My experience has been solely with sqlite3 and postgresql, which are really easy to use.
I am now creating a new app to learn to use mysql. I installed mysql with homebrew (brew install mysql), and created a new rails app that uses mysql rather than sqlite3. I have included the right gem in my gemfile (gem 'mysql2', '~> 0.2.6').
However, I don't know how to proceed. I have not set up anything more in mysql other than to install it on my system, I don't understand anything to do with how you set it up to run, where it stores the database for my app, and so on.
Please could anyone let me know either the next steps, or a tutorial that would get me understanding enough to develop my app to function just as it would with a simpler (sqlite) database system?
I believe the next step would be create the database in "your system" and let Rails know that you want to use that database.
If you want to create the database using the MySQL server directly, you want to log in by using this command from your console:
mysql -u root
By default, mysql root user doesn't need a password, otherwise you would specify it with -p, so it would be:
mysql -u root -p
Once you are logged in your MySQL server, you want to create the database by doing this command:
CREATE DATABASE my_project_database;
You might want to look deeper into users and permissions in MySQL, but this is just a starting point :).
If you want to avoid going into the MySQL server and do it the Rails way, you can create the database using rake. You want to use this command: rake db:create. This will do the same that we did before, but notice that before doing that command you need to create the database.yml file. So let's do that:
You want to have a database.yml file like this:
development:
host: localhost
adapter: mysql2
database: my_project_database
username: root (notice that you might want to change this user later)
password:
I suppose that next step would be to create the Migrations that would generate the tables you want to use and so on.
One of the things that I love the most about Rails is its ORM called Active Record. It will abstract all database operations, so you don't have to worry either if you are calling a MySQL or a SQLite...
Im trying to create my own database with MySQL Workbench and run some queries on it. I have MySQL server 5.1 running and can enter queries in the command line tool to ask for version number and such.
But how do I get the server to host the database that I created in Workbench? When I enter "use MijnDatabase" or "-u root#localhost -p MijnDatabase" it says the database cannot be found. This makes sense, "MijnDatabase" the database file name and it's not connected to the server in any way (also tried with "mydb" wich is the db name I see inside Workbench).
Anyway I'm missing the link between MySQL server and hosting an actual database file.
When you create a database use only lower case letters and use underscore to separate words:
create database my_database;
use my_database;
show tables;
etc...
To connect to your database use:
mysql -u root -p
enter your password then
use my_database;
show tables;
etc...
I have not used MySQL Workbench but the command line and phpMyAdmin. I suggest you start using the command line to learn a little bit MySQL, then use a GUI tool. However the command line is your best teacher.
Have a look in the reference doc: http://dev.mysql.com/doc/refman/5.1/en/create-database.html
. Lean how to create a user and grant him permission on the database.