Nathaniel Smith <[EMAIL PROTECTED]> wrote:
>
> So, my question is -- what is a simple way to reliably corrupt a
> sqlite db so that "PRAGMA integrity_check" will fail?
>
For the SQLite regression tests, we open the database
file separately using fopen() and then write bad stuff
into the middle of the file.
Here is a recipe for generating some corruption that
PRAGMA integrity_check will detect but which will not
cause lasting damage to the database - the damage
can be repaired by running REINDEX - and will not cause
an SQLITE_CORRUPT error.
1. Create a new table: CREATE TABLE test1(x UNIQUE);
The UNIQUE argument is important because we want
an index for this test.
2. Look at the SQLITE_MASTER table to find the ROOTPAGE
for this table. Use fopen() to make a copy of this
page, taking care to remember that SQLite page numbers
begin with 1, not 0.
3. Insert one small row into the test table:
INSERT INTO test1 VALUES(1); Commit this change.
4. Overwrite the rootpage of the test table with the
copy of that page that was saved in step 2. This
effectively deletes the entry you just inserted but
without updating the index - so that the index and
the table are now out of sync.
--
D. Richard Hipp <[EMAIL PROTECTED]>
