Answers for "how to alter table in mysql"

alter table column change data type to text mysql

ALTER TABLE tablename MODIFY columnname INTEGER;

add new column to the table mysql

ALTER TABLE `TABLE_NAME` 
	ADD `COLUMN_NAME` VARCHAR(50) NULL
    AFTER `COLUMN_NAME_AFTER`;

alter table mysql

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

ALTER TABLE nom_table
MODIFY nom_colonne type_donnees

my sql alter table

ALTER TABLE nom_table
DROP nom_colonne