finding duplicates entries


    duplicates = User.find( :all,
  :select     => "email, COUNT(email) AS duplicate_count",
  :conditions => "email IS NOT NULL AND email != ''",
  :group      => "email HAVING duplicate_count > 1"
)
    2009-07-18T01:52:55Z
    having example in rails. from: http://blog.grayproductions.net/articles/five_activerecord_tips
    187
    39
    false
    finding duplicates entries
    2009-07-18T01:52:55Z
    7


    SELECT COUNT(*) AS Total, SUBSTRING_INDEX(email, '@', -1) AS Domain FROM users 
GROUP BY SUBSTRING_INDEX(email, '@', -1) ORDER BY COUNT(*) DESC LIMIT 10;
    2009-07-12T17:47:15Z
    from: http://www.mendable.com/sql-trick-where-are-your-users-from/
    186
    40
    false
    count domain users using sql
    2009-07-12T17:50:03Z
    7


    -- mostra o número de usuários novos criados dia a dia
select date_format(created_at,'%d/%m/%y') as data, count(id) as total from leonardo_supertestes.users group by date_format(created_at,'%m-%d') order by date_format(created_at,'%m-%d');

-- mostra o número de testes feitos dia a dia
select date_format(created_at,'%d/%m/%y') as data, count(rate) as total from leonardo_supertestes.results group by date_format(created_at,'%m-%d') order by date_format(created_at,'%m-%d');

-- conta o número total de usuários
select count(id) from leonardo_supertestes.users;

-- conta o número total de testes feitos
select sum(hits) from leonardo_supertestes.exams;
    2009-05-24T16:45:07Z
    
    177
    40
    true
    autosimulado queries
    2009-05-24T16:45:07Z
    7


    # first, create the method import_sql:

class ActiveRecord::ConnectionAdapters::MysqlAdapter
  def import_sql(file)
    conf = ActiveRecord::Base.configurations[RAILS_ENV]
    sql_file = File.join(RAILS_ROOT, 'db', file + '.sql')
    cmd_line = "mysql -h "+conf["host"]+" -D "+conf["database"]+ " --user="+conf["username"]+" --password="+conf["password"]+" < "+sql_file
    raise Exception, "Error executing " + cmd_line unless system(cmd_line)    
  end
end


# create a migration. ex:

./script/generate migration sql_external_test

# save your sql file with sql commands in db/. migration's sample:

class SqlExternalTest < ActiveRecord::Migration
  def self.up
    import_sql("test")
  end

  def self.down
  end
end


    2009-02-02T18:46:51Z
    it's a small how to import a file in migrations.

from: http://code-ronin.com/articles/rails-migrations-directly-import-sql
    151
    39
    false
    import sql files into migrations
    2009-02-02T18:46:51Z
    7


    ALTER TABLE tablename AUTO_INCREMENT = 1
    2008-07-02T00:31:31Z
    
    10
    40
    false
    resets autoincrement (mysql)
    2008-07-02T00:31:31Z
    7