[SOLVED] Is there AUTO INCREMENT in SQLite?

Is there AUTO INCREMENT in SQLite?

I am trying to create a table with an auto-incrementing primary key in Sqlite3. I am not sure if this is really possible, but I am hoping to only have to designate the other fields.

For example:

CREATE TABLE people (
  id integer primary key auto increment, 
  first_name varchar(20), 
  last_name varchar(20)
);

Then, when I add a value, I was hoping to only have to do:

INSERT INTO people VALUES ("John", "Smith");

Is this even possible?

I am running sqlite3 under cygwin in Windows 7.

Solution

You get one for free, called ROWID. This is in every SQLite table whether you ask for it or not.

If you include a column of type INTEGER PRIMARY KEY, that column points at (is an alias for) the automatic ROWID column.

ROWID (by whatever name you call it) is assigned a value whenever you INSERT a row, as you would expect. If you explicitly assign a non-NULL value on INSERT, it will get that specified value instead of the auto-increment. If you explicitly assign a value of NULL on INSERT, it will get the next auto-increment value.

Also, you should try to avoid:

 INSERT INTO people VALUES ("John", "Smith");

and use

 INSERT INTO people (first_name, last_name) VALUES ("John", "Smith");

instead. The first version is very fragile — if you ever add, move, or delete columns in your table definition the INSERT will either fail or produce incorrect data (with the values in the wrong columns).