mysqli_fetch() return values View as Markdown

I would like to propose a change in how mysqli_fetch() signifies "no
more data." It should return NULL instead of MYSQLI_NO_DATA (a
positive value) because it leads to cleaner PHP code and is more
consistent with other MySQL fetch functions.

Currently, mysqli_fetch() returns one of three different values:

Value | Meaning

true | Successful Fetch
false | Error
MYSQLI_NO_DATA | No more data

Returning the constant MYSQLI_NO_DATA (100) mimics the underlying
MySQL C API, but it leads to non-natural PHP Code:

while (MYSQLI_NO_DATA !== mysqli_fetch($db)) {
// do something.
}

Every other MySQL function allows you to do:

while ($row = mysqli_fetch_row($db)) {
// do something.
}

And I think it'd be much nicer to allow people to write:

while (mysqli_fetch($db)) {
// do something.
}

Therefore, I propose that instead of returning MYSQLI_NO_DATA, we
return NULL. Here's my reasoning:

1. The other mysqli_fetch_* functions now return NULL in this
   situation.
2. We're already modifying the MySQL C-level return values. In C,
   mysql_fetch() returns 0 on success and 1 upon an error. We've
   swapped these values to behave more PHP-like.
3. When 0 signifies success, a positive "no more data" error code
   makes sense because it looks (logically) like an error inside a
   while. That doesn't hold true now that we've flipped these values.

-adam

--
adam@trachtenberg.com
author of o'reilly's php cookbook
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