On 7/4/07, Dan Kennedy <[EMAIL PROTECTED]> wrote:
On Wed, 2007-07-04 at 09:58 +0200, Jef Driesen wrote: > Igor Tandetnik wrote: > > Mario Figueiredo wrote: > >> I'm a tad bit confused with sqlite3_finalize() usage when the query > >> fails. As it is, I'm assuming it releases resources and I use it in > >> this context: > >> > >> -------------------------------- > >> rc = sqlite3_prepare_v2(/* ... */); > >> if (rc != SQLITE_OK) > >> { > >> sqlite3_finalize(stmt); > >> /* ... */ > >> } > > > > This doesn't make any sense. If prepare fails, you do not have a valid > > statement handle to call finalize on. > > > > Igor Tandetnik > > Are you sure about that? The documentation for sqlite3_prepare_v2 says:Igor is, as usual, correct. The situation in 3.4.0 is that if sqlite3_prepare() returns other than SQLITE_OK, you are guaranteed that *ppStmt is set to NULL. You may call sqlite3_finalize() on this if you wish - it's a no-op. Historically, it may have been that *ppStmt was sometimes left uninitialized if an error occured (hence the "may" in the docs). This is in contrast to sqlite3_open(). You must call sqlite3_close(), even if sqlite3_open() returned an error code. Dan. > *ppStmt is left pointing to a compiled SQL statement structure that can > be executed using sqlite3_step(). Or if there is an error, *ppStmt may > be set to NULL. If the input text contained no SQL (if the input is and > empty string or a comment) then *ppStmt is set to NULL. The calling > procedure is responsible for deleting the compiled SQL statement using > sqlite3_finalize() after it has finished with it. > > I also thought this means the statement has to be deleted with > sqlite3_finalize, even when sqlite3_prepare_v2 failed (except for the > case where NULL is returned). Notice the "may be set to NULL" in the > documentation. Doesn't a non-NULL value indicate some memory was > allocated and thus need to be freed?
It's that "may" indeed that caused the confusion and that is still present on the current documentation. I suggest perhaps a review of that paragraph now that it is clear the memory will always be released. ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
