11. MySQL Part 2: UPDATE, ALTER, DELETE, Keys, Constraints and Users

11.3 ALTER TABLE: Add, Modify, Rename and Drop Columns

By Ravindra Bagale · Last updated: 27 September 2026

Table banavlyavar requirement badalte – navin column, mothi size, naav badal. Tyasathi ALTER TABLE.

ALTER TABLE students ADD COLUMN phone VARCHAR(15);                    -- add at the end
ALTER TABLE students ADD COLUMN gender CHAR(1) AFTER name;            -- add after a column
ALTER TABLE students ADD COLUMN batch VARCHAR(20) FIRST;              -- add as first column
ALTER TABLE students MODIFY COLUMN phone VARCHAR(20) NOT NULL DEFAULT '';   -- change type/rules
ALTER TABLE students CHANGE COLUMN phone mobile VARCHAR(20);          -- rename + redefine
ALTER TABLE students RENAME COLUMN mobile TO contact_no;              -- rename only (MySQL 8 / MariaDB 10.5+)
ALTER TABLE students DROP COLUMN batch;                               -- remove column and its data
ALTER TABLE students ADD INDEX idx_city (city);                       -- add an index
ALTER TABLE courses RENAME TO course_list;                            -- rename table
RENAME TABLE course_list TO courses;                                  -- same, other syntax
DESCRIBE students;