my sql alter table
snippet in sql

alter table mysql

user6866

ALTER TABLE contacts
  ADD last_name varchar(40) NOT NULL
    AFTER contact_id,
  ADD first_name varchar(35) NULL
    AFTER last_name;

my sql alter table

user970

ALTER TABLE nom_table
MODIFY nom_colonne type_donnees

my sql alter table

user6018

ALTER TABLE nom_table
DROP nom_colonne