SQL AUTO INCREMENT Field

AUTO INCREMENT Field:

Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table.

Often this is the primary key field that we would like to be created automatically every time a new record is inserted.

  
         CREATE TABLE Persons (
         Personid int NOT NULL AUTO_INCREMENT,
         LastName varchar(255) NOT NULL,
         FirstName varchar(255),
         Age int,
         PRIMARY KEY (Personid)
        );
    

By default, the starting value for AUTO_INCREMENT is 1, and it will increment by 1 for each new record.

To let the AUTO_INCREMENT sequence start with another value, use the following SQL statement: ALTER TABLE Persons AUTO_INCREMENT=100;