I am stating out learning Ruby on Rails. For that I am using "Agile Web Development with Rails 4th edition book" which basically walks you through the creation of a sample project.
Even though I am getting the basics down from it I have failed to understand what I believe is a fundamental concept. Where exactly is the relational database and how can I access it directly?
If I was using PHP/MySQL I would go to phpmyadmin and could query the data directly.
How can achieve this with SQLite3?
I am using Linux (Ubuntu) and installed ror and sqlite with gem.
Thanks.
From your Rails root you can access the database command line directly with:
$ sqlite3 db/development.sqlite3
SQLite version 3.7.5
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>
The SQLite3 database is stored in a file, usually located in the db/ folder. If you use Firefox, I recommend the SQLite Manager addon.
You can use other databases if you want to, see 3.3 Configuring a Database in the getting started guide for rails.
Related
I'm trying to start learning ruby on rails and install sqlite3. I actually installed sqlite3 however it doesn't function well like you can see at the bottom.
ruby 2.5.0p0 (2017-12-25 revision 61468) [x64-mingw32]
C:\Users\abc>sqlite3 --v
'sqlite3' is not recognized as an internal or external command,
operable program or batch file.
C:\Users\abc>
Would you tell me how to solve this problem?
Switching to Ubuntu is easier than learning all the hacks required to get Ruby on Rails working on Windows. Once you switch you will never look back, and all the tools you need, like SQLite, will install very easily.
SQLite is an embedded SQL database engine. Unlike most other SQL databases, SQLite does not have a separate server process. SQLite reads and writes directly to ordinary disk files. A complete SQL database with multiple tables, indices, triggers, and views, is contained in a single disk file.
Directly downloadable SQLite .exe file to maintain database SQLite then extract to a folder then open SQLite command toll where you can command for database creation, delete, edit or view
You need marked one .exe file, double-click to open then write command which you need.
I have crm rails application deployed in heroku so my database is postgresql. I have an iphone app which is using mysql database. Now what i need to do is to synch my iphone database with my heroku database.
Can anyone please help me on this is it possible to sync two different databases in heroku
Thanks in Advance
The way we did this was to do it manually
Yep, it's a real pain, but at least you know it's done correctly
--
Process
For migrating from Postgres to MYSQL is as follows:
"Backup" the database using pg_backups
Download the backup locally
In MYSQL (we used PHPMyAdmin), create a series of SQL calls to insert the respective data into the correct tables
Migrating from MYSQL to Postgres is, as much as I can determine, a similar process:
Download the SQL dumps of your MYSQL DB (I only know how to do this in PHPMyAdmin)
Configure those files to be "PG" ready
Send the SQL to your Heroku postgres db's
--
Notes
For specifics, I only have the following:
If you dump from Heroku, you'll not get a traditional SQL file; you'll receive a .dump file. To change this, you'll need to use pg_restore in the following way:
$ cd c:/your/postgres/install/pg_restore/location
$ pg_restore path_to_your_dump.dump > path_to_your_sql.sql
This will give you the ability to "read" the file, uploading to your db & importing as you wish. That's when the fun begins :)
Importing MYSQL
The way to import MYSQL into a PG db will have to be done manually
Although we've never done this directly (we only migrated from PG), there are several things you can do. Firstly, you can use the PG2MYSQL converter to give you an idea as to the syntax differences between MYSQL & PG
Then I would perform a "dump" from MYSQL in SQL format. This will give me the data required for PG. This will allow me to insert into my PG database (you might have to do this locally to give you the ability to determine the syntax), from which you can then patch in the MYSQL data
I understand it's not the most elaborate explanation - I hope it gives you some ideas
Im learning Ruby on Rails 3 and would like to see the db structures created by various Scaffold commands in Sqlite3 in order to understand more the process.
In OSX Snow Leopard, entering:
which sqlite3
yields:
"/usr/local/bin/sqlite3"
However cant seem to find the databases! Pointing to that location merely yields the following error message:
connection failed. file is encrypted or is not a database
To view the dbs im using:
Navicat for Sqlite
anyone enlighten me where the dbs actually reside? "/usr/local/bin/sqlite3" seems to be an symlink to: /usr/local/Cellar/sqlite/3.7.10/bin/sqlite3s
SQLite is actually serverless, so the DB files by default reside in your rails directory.
For example:
/db/development.sqlite3
You can check where all your sqlite environment databases are on config/database.yml
Currently I get the following error:
PGError (FATAL: password authentication failed for user "postgres" ):
when my app tries to access the database.
I wanted to test my SQL calls against postgres as my app regular breaks when pushed up to production on Heroku because of the stricter requirements of postgres (which I think is probably a healthy thing) over sqlite 3. So I have a similar request to this for a not out of date tutorial for installing postgres for use with ruby on rails on windows (7) please. I thought it'd be a quick 20 minutes of downloading and installing but 2 and a bit hours later and I don't think I'm very close yet. So far I've:
Downloaded and installed Postgres Version 8.4.8-1 from here
Set my environment variables such that Path (for User) is: C:\Ruby192\bin;C:\Program Files (x86)\PostgreSQL\8.4\bin
Gemfile:
gem 'pg', '0.11.0' # instead of gem 'sqlite3', '1.3.3'
ran bundle install for my rails app seemingly successfully, but haven't found easy way to validate installation yet.
set database.yml as suggested here to:
development:
adapter: postgresql
database: db/development
username: postgres
password: secret
host: localhost
encoding: UTF8
pool: 5
timeout: 5000
I know I need to set up a user name and password for Postgres, maybe also start the postgres server, connect to it(?) and put in my local IP address I'll connect to it on into a config files somewhere and then edit one of the other .conf files in 'C:\Program Files (x86)\PostgreSQL\8.4\data' etc...
I think Rails has made me soft, am I over thinking things or is it actually fairly tricky to set up and I should just go back to Sqlite3, for which there's also the awesomely useful SQLite Manager, Firefox plugin?
I'm still searching for a beginners guide to installing and using Postgres for rails but so far have only been confused by most of the stuff I look at / tried following like this, this, this, this, this(for Snow Leopard), this(linux).
Any pointers would be much appreciated. Thanks!
James
An approach to installing Postgres on windows 7 for use as PostgreSQL database for a rails 3 (3.0.7) project.
Preamble (you can skip this bit)
So the first thing to point out is that Postgres is not just a different file extension from .sqlite3, it's a whole mechanism for managing your databases. As such it has a client/server model, of which you'll need to set up both to use Postgres as the database for your rails app.
Motivation for going through considerable pain of Postgres setup versus almost effortless sqlite setup: if you're deploying to Heroku, they're currently using Postgres so some of your SQL calls that are fine on sqlite3 will break when used with Postgres. It's much easier to debug postgres locally rather than when it's on Heroku's servers.
So I did the following things:
(Disclaimer: I may have forgotten to include some of the things I did... it took me over 48 hours of on and off pain to get it to work... if the following advice doesn't work for you then the huge (2300 pages!!) but very thorough Postgres documentation should help. I'd recommend downloading this anyway if you're serious about using Postgres as it has a lot of material that I've only just begun to understand the significance of.)
(Second disclaimer: I have almost certainly broken 20 sensible Postgres guidelines and exposed security holes in the Postgres database whilst doing so. If there any obvious things an experienced Postgres user disagrees with, please edit my post.)
.Step 1. Download and install PostgreSQL v9.0.4-1 from here because here said only 9.0.x would be supported on windows 7. I kept all the default options and just used 'secret' as the password when prompted by the Postgres installer for one (again not entirely sure what the consequences of sharing that info on the internet is... will soon find out I'm sure). You'll need this password in step 3.
.Step 2. Change environment variables such that Path (for system, not user (I'm not sure if this is significant or not)) is: C:\Program Files\PostgreSQL\9.0\bin
(n.b. I'm on 64-bit windows hence it not being installed for 32-bit in 'C:\Program Files (x86)\PostgreS...')
Don't forget to change access rights to folder PostgreSQL\9.0 and remove any default readonly rights on the folder or content.
(You may also need to restart your computer for these to take effect - thanks #Gavin -although not likely).
.Step 3. Test Postgres installation by trying to create a new database:
From command line: createdb -U postgres mydb_as_postgres.
You should be prompted to enter the password now, if you're not it may be that you need to start the server first (I can't remember whether I needed to do this or not). The easiest way is through pgAdmin III, which should be 'pgAdmin3.exe' in a folder somewhere like C:\Program Files\PostgreSQL\9.0\bin. Once you've started pgAdmin III there should be a panel on the left called 'Object Browser'. In this there should be a tree with:
Server Groups > Servers > PostgreSQL 9.0 (localhost:5432)
Right click on 'PostgreSQL 9.0 (localhost:5432)' and select 'Connect'.
The createdb -U postgres mydb_as_postgres command should create a new databse called 'mydb_as_postgres' which you can check by firing up pgAdmin III and double clicking on 'PostgreSQL 9.0 (localhost:5432)'. Under this there should be:
Databases (2) which should list 2 databases called mydb_as_postgres and postgres
I called it _as_postgres because the -U postgres part of the command tells Postgres to create the database with the postgres user as it's owner, which you need to specify when you're not signed in as the postgres user. I have all of my files stored as 'AJames' user though so if you're the same and want to keep developing your app when signed in as a different user you need to create a Postgres 'role' for that user now (see step 4).
.Step 4. Through pgAdmin III. Right-click on Login Roles (which for me is in):
Object Browser > Server Groups > Servers > PostgreSQL 9.0 (localhost:5432) > Login Roles
Right-click on Login Roles and select 'New Login Role...'
in Role name, put in your operating system user name, which for me is AJames,
and fill in your password under the 'Role Privileges' tab, I checked all the boxes, but an experienced postgres user would likely strongly recommend to only check the 'inherits rights from parent roles' and the 'can create database objects' But I'm not an experienced user and just want to debug Rails SQL calls in Postgres so I also checked the 'Superuser' and 'Can create roles', just in case.
.Step 5. You should now be able to create a new database without being signed in as the postgres user. Try typing:
createdb mydb_as_user
Hopefully this should work for you.
.Step 6. Okay, so you've got a development.sqlite3 file in your rails 'db/' directory. Initially I was going to set the next test as converting this from sqlite3 to psql.
I couldn't get this to work though but I left my attempts here as the solution I used required having the data in a Rails app on Heroku.com (see instead the solution from step 7 onwards). For those who only have a local app and no data in Heroku, they can't use the same approach, so they might need to explore something like this:
x6.1 First, test 'psql' by trying a command from your command line like:
psql mydb_as_user
this should display something like below (after you've typed in your password):
C:>psql mydb_as_user
Password:
psql (9.0.4)
WARNING: Console code page (850) differs from Windows code page (1252)
8-bit characters might not work correctly. See psql reference
page "Notes for Windows users" for details.
Type "help" for help.
mydb5=#
x6.2 try entering:
CREATE TABLE users_table (id integer, "name" text);
It should display:
CREATE TABLE
mydb5=#
If you check in pgAdmin III, you should see the table there under:
Object Browser > Server Groups > Servers > PostgreSQL 9.0 (localhost:5432) > Databases > mydb_as_user > Schemas > public > Tables > users_table >
x6.3 Okay, next to try the conversion. Downloaded sqlite-shell precompiled binary for windows.
x6.4 Create a new directory, I used 'C:\temp' and put the sqlite3.exe and your development.sqlite3 files in it.
x6.5 Use the following commands (which are from here) to dump the development.sqlite3 database into Postgres.
sqlite3 development .dump | psql development2
you might get an error like:
psql: FATAL: database "development2" does not exist
x6.6 so I went into pgAdmin III and made a development 2 database, tried the command again and got:
ERROR: syntax error at or near "PRAGMA"
LINE 1: PRAGMA foreign_keys=OFF;
^
BEGIN
COMMIT
Like I said, I couldn't get it to work. I'm sure there's a way of getting round that error but I thought of a different way and so I instead used this solution (which requires a Heroku account to have your data and does the conversion from sqlite3 to psql using the Taps gem (I believe):
.Step 7. in pgAdmin III I created another database. Under the properties tab I set name: 'development', owner: 'AJames' (replace this with your own Windows user name). And under the privileges tab, set role: 'public' and checked the ALL option (thought this resets to unchecked so I'm not sure that's necessary).
.Step 8. add
gem 'pg', '0.11.0'
to your gem file. You'll probably also want to remove the:
gem 'sqlite3'
at this point too.
.Step 9. set database.yml as suggested here to:
development:
adapter: postgresql
database: db/development
username: AJames # replace this with your own user name
password: secret # replace this with your own password
host: localhost
encoding: UTF8
pool: 5
timeout: 5000
If you are working on an open source project and don't want your password to be made publicly available, have a look at some of the answers to Securely providing the database password in a Rails app.
.Step 10. from command line in your rails app's root directory run:
rake db:migrate
This will create the new schema and all the tables in the Postgres database.
.Step 11. run heroku db:pull from your command line (again from in the root directory of your rails app) to pull all your data down and into your new empty Postgres database. I think at this point your taps gem will be doing this work for you.
.Step 12. Hopefully there is no step 12! ...and it should now be working for you. Happy RoR PostgreSQL debugging! Please edit, or let me know, if there are any errors in this.
Also, here's a list of additional stuff that might be interesting/useful:
This is a blog post about Postgres passwords, what they're for,
why you need them, how to change them etc.
This, under 'Creating a spatial database', is useful for newbies to
understand what pg_hba.conf is about and the second link that
Reno gave above, under the 'Using pgAdmin III GUI' is useful to
testing to see if postgres is actually working, before trying to fit
it with Rails (i.e. try creating a database and putting a table and
some data into it).
In the huge but very comprehensive Postgres documentation, I'd
start on page 58, 'I. tutorial'. Then on pdf page 431(!) there's
'Chapter 17. Server setup and operation' that I also found useful.
the answer from AJP is the correct one with just a small re-config.
The line
database: db/development
does not work for me.
I have to change it to
database: development
I use this for ruby on rails for the command
rake db:create
and
rake db:migrate
to work
None of your links appeared to be the (arguably) most useful documentation - the official postgresql docs. I recently configure a Linux Mint box with postgresql and django using a combination of those documents and these, though the latter are specific to Linux.
I'd worry more about validating the postgresql side of things, less about rails. That is to say, your question should be "How can I set up and test a postgresql server on a Windows 7 box", moreso than you need to know how to get it locked into rails.
Edit:
Maybe this could also be of use to you - official postgresql wiki with detailed installation guides.
Good luck!
I'm new to Ruby on Rails (PHP developer here) and I need to edit an existing ROR project. I've been using Aptana Studio for my PHP projects (switched to Zend after Aptana 2.0) but I've kept Aptana RadRails for my ruby projects.
So what I want to do is to get the ROR project from the server (it's hosted on some linux machine) and import it into RadRails for local development. I've downloaded the files from the server and imported them in a new RadRails ROR project but it doesn't work as intended. Is there anything else I should do ? I've read about 'freezing the gems', switching to production mode and dumping the database for a ROR project upon releasing. Are there some steps needed to undo those operations ?
UPDATE:
The problem that I'm having is that I get various errors when trying to visualize in the browser the pages for different controllers.
ActionController::InvalidAuthenticityToken in
No :secret given to the #protect_from_forgery call. Set that or use a session store capable of generating its own keys (Cookie Session Store).
OR
no such file to load -- xml
This error occurred while loading the following files:
hotels_pro
xml
This leads me to believe that (maybe) I haven't got all the files. On the other hand I have double-checked and I have all the files from the server.
Thanks,
A RoR application is more than just the sum of its source files. There's also the database, gems and a server which exist outside the project directory. Without knowing exactly what doesn't we can only speculate which is causing you problems. Being new to Rails, it's probably all of them. If after all this you're still not up and running a few rounds of "Google the Error" should fix you up.
You'll need to set these things up in your development environment before you can proceed. The following assumes you have a working ruby environment: rubygems installed with the rails, and rake gems. Note any commands and paths that follow are relative to the root of your rails project.
Database:
Start with editing config/databases.yml to find out which database your app will try to connect to. Change it if necessary so it names a local database. Create that database, if it doesn't exist with $rake db:create
If you need existing data to test with you can take a dump from your production database and import it into your working database. How to do this is dependent on the type of database in question. Otherwise you can run the migrations with $ rake db:migrate to produce your development database (assuming the previous developer designed the database with migrations.)
Gems:
Check the config/environment.rb, for your list of required gems. Install all these gems if they haven't been already.
If you're using Rails 2.1 or newer, you can streamline this process by ensuring that all gems are required using the newer config.gem 'this_gem' form instead of older require 'this_gem' declaration. Once all required gems are in this form, you can use $ rake gems:install && rake gems:build to ensure they're all installed.
Server:
Is pretty trivial, all rails instalations come with web brick which is fine for development. But mongrel is also suitable.
P.S. If you're not using some kind of revision control it's strongly advised to set something up before starting. It's not a requirement, but it will likely save your ass at some point.