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Type:
Bug
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Status: Closed (View Workflow)
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Priority:
Minor
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Resolution: Fixed
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Affects Version/s: 5.5, 10.0, 10.1, 10.2, 10.3, 10.2.13
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Fix Version/s: 5.5.60
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Component/s: Optimizer
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Labels:
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Environment:docker with mariadb:latest (host is a debian testing)
10.2.13-MariaDB (tested on docker latest)
MariaDB [(none)]> SELECT 1 from DUAL WHERE 1 != 1; |
Empty set (0.00 sec) |
Ok.
Exhibit A :
MariaDB [(none)]> SELECT 2 IN (SELECT 1 from DUAL WHERE 1 != 1); |
+----------------------------------------+ |
| 2 IN (SELECT 1 from DUAL WHERE 1 != 1) | |
+----------------------------------------+ |
| 0 |
|
+----------------------------------------+ |
|
|
1 row in set (0.00 sec) |
Ok.
2 is indeed not in the empty set
Exhibit B :
MariaDB [(none)]> SELECT 2 IN (SELECT 2 from DUAL WHERE 1 != 1); |
+----------------------------------------+ |
| 2 IN (SELECT 2 from DUAL WHERE 1 != 1) | |
+----------------------------------------+ |
| 1 |
|
+----------------------------------------+ |
|
|
1 row in set (0.00 sec) |
Not ok.
I thought 2 was not in emptyset. why changing the emptyset did affect that ?
Exhibit B looks like a DUAL bug, as :
- it returns 0 if we replace DUAL by any other table
- it returns 0 if I use a mysql backend instead