Rails number db format

migration.rb

  t.integer :int                 # int (4 bytes, max 2,147,483,647)
  t.integer :int1, :limit => 1   # tinyint (1 byte, -128 to 127)
  t.integer :int2, :limit => 2   # smallint (2 bytes, max 32,767)
  t.integer :int3, :limit => 3   # mediumint (3 bytes, max 8,388,607)
  t.integer :int4, :limit => 4   # int (4 bytes)
  t.integer :int5, :limit => 5   # bigint (8 bytes, max 9,223,372,036,854,775,807)
  t.integer :int8, :limit => 8   # bigint (8 bytes)
  t.integer :int11, :limit => 11 # int (4 bytes)