sql id auto increment code example

Example 1: how to auto increment in sql

CREATE TABLE Persons (
    Personid int NOT NULL AUTO_INCREMENT,
    LastName varchar(255) NOT NULL,
    FirstName varchar(255),
    Age int,
    PRIMARY KEY (Personid)
);
INSERT INTO Persons (FirstName,LastName)
VALUES ('Lars','Monsen');

Example 2: oracle auto_increment

-- Use a sequence:
CREATE SEQUENCE id_seq START WITH 1;
INSERT INTO my_table (ID, VALUE) VALUES (id_seq.NEXTVAL, 'My value');

Example 3: id increment ms sql server

CREATE TABLE Persons (
    Personid int IDENTITY(1,1) PRIMARY KEY,
    LastName varchar(255) NOT NULL,
    FirstName varchar(255),
    Age int
);

Example 4: how to alter auto increment in sql

INSERT INTO Persons (Personid,FirstName,LastName)

VALUES (seq_person.nextval,'Lars','Monsen');

Example 5: what is auto increment in sql

Autoincrement keyword allows the
user to create a unique number to get
generated whenever a new record is
inserted into the table.
This keyword is usually required 
whenever PRIMARY KEY in SQL is used.