Fix simulate query count#18583
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Codecov ReportPatch coverage:
Additional details and impacted files@@ Coverage Diff @@
## QA_5_2 #18583 +/- ##
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- Coverage 48.20% 47.27% -0.94%
- Complexity 17010 17011 +1
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Files 607 607
Lines 72335 72342 +7
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- Hits 34870 34200 -670
- Misses 37465 38142 +677
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@MoonE Could you please rebase the PR? |
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Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
Signed-off-by: Maximilian Krög <maxi_kroeg@web.de>
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| return 'SELECT COUNT(*)' . | ||
| ' FROM (SELECT ' . implode(',', $newValues) . ') AS `pma_new`' . | ||
| ' JOIN (' . | ||
| 'SELECT ' . implode(', ', $oldValues) . ' FROM ' . $tableReferences[0] . $where . $order . $limit . | ||
| ') AS `pma_old`' . | ||
| ' WHERE NOT (' . implode(', ', $newColumns) . ') <=> (' . implode(', ', $oldColumns) . ')'; |
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I'd love if there was some comment explaining how this works because I can't comprehend it myself. :)
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pma_new selects the set values into a single row which is then joined with the current table as pma_old. No ON condition needed, as pma_new is always just a single row.
In the WHERE condition a tuple comparison is made that checks if the old data tuple is different to the new data tuple.
The outer select counts all rows that are different.
UPDATE `table_1` SET `id` = 1, `name` = 'asdf' WHERE `id` = 10SELECT COUNT(*)
FROM (SELECT 1 AS `n0`, 'asdf' AS `n1`) AS `pma_new`
JOIN (SELECT `id` AS `o0`, `name` AS `o1` FROM `table_1` WHERE `id` = 1) AS `pma_old`
WHERE NOT (`n0`, `n1`) <=> (`o0`, `o1`)Thinking about it ... this should be equivalent to this, placing the values directly in the WHERE condition:
SELECT COUNT(*)
FROM (SELECT `id` AS `o0`, `name` AS `o1` FROM `table_1` WHERE `id` = 1) AS `pma_old`
WHERE NOT (1, 'asdf') <=> (`o0`, `o1`)There was a problem hiding this comment.
@MoonE I'm not sure about COUNT(*). Previously, when the number was clicked it would have shown the rows that will be updated, but now is only the count number.
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The count is the number of updated/affected rows. The pma_old subquery will give the matched rows, and the where condition reduces this to the affected rows
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The count is the number of updated/affected rows. The
pma_oldsubquery will give the matched rows, and the where condition reduces this to the affected rows
Yeah, but when the number is clicked, previously the rows where shown, something like:
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I did not know about that ...
Though I'm not sure how useful this feature is. Just listing the updated values without a full row context?
It does make sense when deleting rows ...
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I did not know about that ...
Though I'm not sure how useful this feature is. Just listing the updated values without a full row context?
Well, the feature was there and probably someone might use this.
Fixes #18533, closes #18536