On Dec 24, 2015, at 9:14 AM, Simon Slavin <slavins at bigfraud.org> wrote:
>
> ALTER TABLE DROP COLUMN ...
>
> ...the way SQLite3 is written makes it difficult or inefficient to implement
> them.
I wouldn?t mind if SQLite did nothing more than the recommended manual process
for emulating the ALTER TABLE affordances in other DBMSes which are missing in
SQLite.
For my purposes, the table copy isn?t the problem, the problem is that a simple
one-liner in other DBMSes becomes a dozen lines in SQLite:
BEGIN TRANSACTION;
ALTER TABLE Foo RENAME TO oldFoo;
CREATE TABLE Foo ? a bunch of repeated stuff
? almost identical to the initial
? DBMS creation code with just one
? or two differences yet everything
? that has stayed the same still has
? to be repeated just because SQLite
? doesn?t fully support ALTER TABLE
INSERT INTO Foo SELECT some,subset,of,columns FROM oldFoo;
COMMIT;
It would be entirely possible for SQLite to generate and run this code for me.
Writing such code is a waste of human brain power.
