Ruby - Iterate through records found with SQL statement

Question

I have a bunch of records found with this SQL

select id from employee_holiday_years where start_date = '2015-01-01' and employee_id in(select id from employees where join_date > '2014-12-31') and allowance_from_last_year <> 0;

I need to iterate through the records returned by this SQL using Ruby and run a couple of Ruby commands against each one. Is this possible?

Answer 1

By ruby you can try this lets you have mysql adapter and ruby installed Also you have

Database Name TESTDB username testuser password test123 host: localhost

  require "dbi"

  begin  
   dbh = DBI.connect("DBI:Mysql:TESTDB:localhost", 
                    "testuser", "test123")
   sth = dbh.prepare("select id from employee_holiday_years where start_date = '2015-01-01' and employee_id in(select id from employees where join_date > '2014-12-31') and allowance_from_last_year <> 0;")
   sth.execute(1000)

   #iterate through the return records 
   sth.fetch do |row|
    printf row[0], row[1] #to print the row

   end
   sth.finish

  rescue DBI::DatabaseError => e
   puts "An error occurred"
   puts "Error code:    #{e.err}"
   puts "Error message: #{e.errstr}"
  ensure
   # disconnect from server
   dbh.disconnect if dbh
  end

For more Ruby Database Access

Answer 2

sql return Array so use Array iteration.

eg

recoreds.each do |record|
  p record.inspect
end   

Answer 3

This is what I came up with

client = Mysql2::Client.new(:host => "localhost", :username => "root", :database => "mydatabase")
results = client.query("select * from mytable where...", :symbolise_keys => true)

results.each do |row|
  do stuff...
end