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37 lines
1.4 KiB
Plaintext
Executable File
37 lines
1.4 KiB
Plaintext
Executable File
This is an extension that aims to implement some efficient data access
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interfaces and classes.
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SPL allows to hook into foreach. Doing so you can do something like
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this:
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$obj = new whatever();
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foreach($obj as $key => $value) { ... }
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This is meant to be used for database access. For example you could
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grab my patch to sqlite (<a href="http://marcus-boerger.de/php/ext/sqlite/">http://marcus-boerger.de/php/ext/sqlite/</a>) and
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look at the oo tests:
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$db = new sqlite($filename);
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foreach($db->query("SELECT....") as $row) { ... }
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SQLite offers four access strategies:
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1) sqlite_query + sqlite_fetch_array
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2) sqlite_unbuffered_query + sqlite_fetch_array
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3) sqlite_query + iterators (sqlite_current)
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4) sqlite_unbuffered_query + iterators (sqlite_current)
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1) and 3) do "over eager evaluating" since they fetch all rows directly.
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2) does "eager evaluating". It always fetches the next row but doesn't
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keep the current row, so that it must be stored elsewhere if it must be
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accessed more then once. For instance this happens when you need to access
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columns separately.
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4) does "eager evaluating". But in contrast to 2) it keeps the current row
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hence its name.
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There is no efficient way for "lazy or just in time evaluating" so 4) should
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be the best case. And 4) also enables the foreach trick.
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To implement 3) and 4) with other db extensions ask me and wait for LT to pass.
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