add column auto increment prmery key mysql code example

Example 1: mysql alter column auto increment

ALTER TABLE document MODIFY COLUMN document_id INT auto_increment

Example 2: insert into auto increment mysql

/* To insert into an auto incrementing field without specifing every column in
the table, you can use the key word default in the place of the auto 
incrementing column*/

INSERT INTO my_table VALUES(default, "test1", 222)
/*VS */
INSERT INTO my_table(name, num) VALUES("test1", 222)
/*Having to type out all of the column names except the auto incrementing one
can be very tedious when you have many columns, just use the keyword defualt
instead and you only have to type it once.

Example 3: how to change the auto increment in existing table mysql

ALTER TABLE tbl_access ADD COLUMN `access_id` int(10) NOT NULL PRIMARY KEY AUTO_INCREMENT FIRST