Ruby Database tables Add fields, modify field types, modify field names

Rails Brochure

3.8 Use changeMethod

1. Add a field to a table

Rails g Migration Add_column_to_d_groups_equip_num

class Addcolumntodgroupsequipnum < activerecord::migration[5.1]  def change add_column:d _groups,: Equip_num,: Integer endend

2. modifying table field types

Rails g Migration Change_column_to_d_groups_equip_num

class Changecolumntodgroupsequipnum < activerecord::migration[5.1]   def  Change      change_ Column:d _groups,: Equip_num,: string   endend

3. Modify the name of the table field

Rails g Migration Change_column_to_d_groups_equip_num_equio_nums

class Changecolumntodgroupsequipnumequipnums < activerecord::migration[5.1]  def Change    rename_column:d _groups,: equip_num,: equip_nums  endend

Ruby Database tables Add fields, modify field types, modify field names