fix: support empty IN clause across all dialects#6887
Merged
imnotjames merged 2 commits intotypeorm:masterfrom Oct 15, 2020
Merged
fix: support empty IN clause across all dialects#6887imnotjames merged 2 commits intotypeorm:masterfrom
IN clause across all dialects#6887imnotjames merged 2 commits intotypeorm:masterfrom
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we were supporting an empty `IN` clause for MySQL and Oracle and this updates the handling to be for all other dialects as well by making the "empty" clause be `0=1` fixes typeorm#2195
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The test commit had CI ran against it to show the failures - the results can be found here |
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From a performance standpoint, all query optimizers that I've checked prevent the query from even doing any work (EG, this will turn the entire query into a no-op, so no table scan happens). The negation turns the expression itself into a no-op and it has no effect on the query. I checked this against the following databases via an EXPLAIN or comparable tool:
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Cool, thanks for working on this |
zaro
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Jan 12, 2021
we were supporting an empty `IN` clause for MySQL and Oracle and this updates the handling to be for all other dialects as well by making the "empty" clause be `0=1` Closes typeorm#4865 fixes typeorm#2195
This was referenced Jan 29, 2021
This was referenced Oct 20, 2021
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we were supporting an empty
INclause for MySQL and Oracleand this updates the handling to be for all other dialects as well
by making the "empty" clause be
0=1This follows the lead of a number of other projects in a similar space:
1=01!=11=01!=1I've also chosen to use
1=0in the empty case because it's the most likely technique which allows the various query optimizers to do their magic. :)Closes #4865
fixes #2195