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ef3a5a1385
When CASE hits a multivalued field it was previously either crashing on fold or evaluating it to the first value. Since booleans are loaded in sorted order from lucene that *usually* means `false`. This changes the behavior to line up with the rest of ESQL - now multivalued fields are treated as `false` with a warning. You might say "hey wait! multivalued fields usually become `null`, not `false`!". Yes, dear reader, you are right. Very right. But! `CASE`'s contract is to immediatly convert its values into `true` or `false` using the standard boolean tri-valued logic. So `null` just become `false` immediately. This is how PostgreSQL, MySQL, and SQLite behave: ``` > SELECT CASE WHEN null THEN 1 ELSE 2 END; 2 ``` They turn that `null` into a false. And we're right there with them. Except, of course, that we're turning `[false, false]` and the like into `null` first. See!? It's consitent. Consistently confusing, but sane at least. The warning message just says "treating multivalued field as false" rather than explaining all of that. This also fixes up a few of CASE's docs which I noticed were kind of busted while working on CASE. I think the docs generation is having a lot of trouble with CASE so I've manually hacked the right thing into place, but we should figure out a better solution eventually. Closes #112359
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12 lines
404 B
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// This is generated by ESQL's AbstractFunctionTestCase. Do no edit it. See ../README.md for how to regenerate it.
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*Parameters*
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`condition`::
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A condition.
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`trueValue`::
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The value that's returned when the corresponding condition is the first to evaluate to `true`. The default value is returned when no condition matches.
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`elseValue`::
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The value that's returned when no condition evaluates to `true`.
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