How do you manually execute SQL commands in Ruby On Rails using NuoDB

Reposting the answer from our forum to help others with a similar issue:

@connection = ActiveRecord::Base.connection
result = @connection.exec_query('select tablename from system.tables')
result.each do |row|
puts row
end

res = ActiveRecord::Base.connection_pool.with_connection { |con| con.exec_query( "SELECT 1;" ) }

The above code is an example for

1. executing arbitrary SQL on your database-connection
2. returning the connection back to the connection pool afterwards

For me, I couldn't get this to return a hash.

results = ActiveRecord::Base.connection.execute(sql)

But using the exec_query method worked.

results = ActiveRecord::Base.connection.exec_query(sql)

The working command I'm using to execute custom SQL statements is:

results = ActiveRecord::Base.connection.execute("foo")

with "foo" being the sql statement( i.e. "SELECT * FROM table").

This command will return a set of values as a hash and put them into the results variable.

So on my rails application_controller.rb I added this:

def execute_statement(sql)
  results = ActiveRecord::Base.connection.execute(sql)

  if results.present?
    return results
  else
    return nil
  end
end

Using execute_statement will return the records found and if there is none, it will return nil.

This way I can just call it anywhere on the rails application like for example:

records = execute_statement("select * from table")

"execute_statement" can also call NuoDB procedures, functions, and also Database Views.