MySQL AUTO INCREMENT constraint is used for sequentially automatically generating numeric values every time a record is inserted into a table. AUTOINCREMENT allows unique value. Often, we use AUTOINCREMENT with PRIMARY KEY constraints.
MySQL uses the AUTO_INCREMENT keyword to perform an auto-increment feature.
Example:-
CREATE TABLE Employee(
ID int AUTO_INCREMENT PRIMARY KEY,
ename varchar(255),
emailid varchar(255),
ephone varchar(15),
ecity varchar(25),
UNIQUE KEY unique_email (emailid)
);
By default, AUTOINCREMENT starts from 1. But if we define start AUTOINCREMENT value then AUTOINCREMENT will start from there:-
Example:-
ALTER TABLE employee AUTO_INCREMENT=50;
If we define AUTOINCREMENT for ID then when we INSERT any value, then no need to define any value for ID.
Example:-
INSERT INTO employee (ename, emailid, ephone, ecity)
VALUES (Raj Singh,’raj@test.com’, 9957231323, Sira);