Create AutoIncrement column/field in Apache Derby
While creating a table a particular column / field can be made autoincrement as :
CREATE TABLE students ( id INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1), name VARCHAR(24) NOT NULL, address VARCHAR(1024), CONSTRAINT primary_key PRIMARY KEY (id) ) ;
The value of an autoincrement column increments automatically with every insert and doesnt need to be specified in the insert command. It is 1 + the value of the same field in the previous row.
Now data can be inserted as :
insert into students(name , address) values('Sanjay' , 'New Delhi');
Note that the value for the id field (which is an autoincrement field) is not specified. It fills automatically by taking the value of the previous row and adding 1 to it.