PDO SQLite query zero result issue

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太阳男子
太阳男子 2021-01-19 04:09

I\'ve had a look around but can\'t seem to find any information on this. I\'m not sure if it\'s an issue with my code or a known issue with in-memory SQLite databases and PD

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  •  鱼传尺愫
    2021-01-19 04:49

    PDOStatement::rowCount() returns

    ... the number of rows affected by the last DELETE, INSERT, or UPDATE statement executed by the corresponding PDOStatement object.

    If the last SQL statement executed by the associated PDOStatement was a SELECT statement, some databases may return the number of rows returned by that statement. However, this behaviour is not guaranteed for all databases and should not be relied on for portable applications.

    Welcome to PDO, where the easy stuff works and the not-so-easy stuff ruins your day. SQLite is one of the drivers that doesn't have a reliable "how many rows are in my result set?" function. From the comments:

    As of SQLite 3.x, the SQLite API itself changed and now all queries are implemented using "statements". Because of this, there is no way for PDO to know the rowCount of a SELECT result because the SQLite API itself doesn't offer this ability.

    A return of false from PDOStatement::fetch() is a guarantee of "nothing came back," and your checking code is entirely sane, if a bit hard to read. You may wish to consider wrapping or deriving from PDO and PDOStatement for your own sanity.

    (Disclaimer: I am a PDO fanboy.)

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