Question

Is it possible without using triggers (if not then a working trigger would still be useful) to auto-increment a field by multiplying it?

E.g. I want the value of the fields to increase like so if I set it to multiply by 2:

1 - 2 - 4 - 8 - 16 - 32 - 64 - 128 - 256 - 512 - 1024 - 2048

Incase you were wondering this is to easier facilitate bitwise operations

Answer 1

When you set up a table, create an auto-increment field, but don’t set it as the primary key. Create a blank field for the primary key. Now, whenever you run a query, just set the primary key to the value of the 2^(auto-increment field value).

Edit: field1 is primary key, field2 is auto-increment, field3 is data.

INSERT INTO table (field3) VALUES ("data");
SELECT LAST_INSERT_ID();
UPDATE table SET field1 = POW(LAST_INSERT_ID(),2);