Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.2(EOL)
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10.2.6-3
Description
MariaDB [test]> create table t1 (a int, check(a>0 or a is null)); |
Query OK, 0 rows affected (0.41 sec) |
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MariaDB [test]> insert into t1 values (null); |
Query OK, 1 row affected (0.06 sec)
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MariaDB [test]> alter table t1 modify a int auto_increment primary key; |
ERROR 4025 (23000): CONSTRAINT `CONSTRAINT_1` failed for `test`.`#sql-4c9e_4` |
If there were no CHECK, a column would have been given the value 1 which actually satisfies the condition.
MariaDB [test]> set check_constraint_checks=0; |
Query OK, 0 rows affected (0.00 sec) |
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MariaDB [test]> alter table t1 modify a int auto_increment primary key; |
Query OK, 1 row affected (1.01 sec)
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Records: 1 Duplicates: 0 Warnings: 0
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MariaDB [test]> select * from t1; |
+---+ |
| a |
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+---+ |
| 1 |
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+---+ |
1 row in set (0.00 sec) |
But apparently the column gets the intermediate value 0 which is checked before the auto_increment is applied.
Attachments
Issue Links
- relates to
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MDEV-7563 Support CHECK constraint as in (or close to) SQL Standard
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- Closed
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Activity
I have merged the final version of the fix, committed in https://github.com/MariaDB/server/commit/38af34bb2143f2a7ce82d2e241d8995f419a7f29, into the 10.2 branch.
I have merged the final version of the fix, committed in https://github.com/MariaDB/server/commit/38af34bb2143f2a7ce82d2e241d8995f419a7f29, into the 10.2 branch.
By making this fix, you've denied using columns in kind of 'recursive' approach.
I have this table which defines nodes and hierarchy between them
create table `track_tree` (
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`node_id` bigint not null auto_increment primary key,
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`parent_node_id` bigint,
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constraint `track_tree_node_id_parent_node_id_ck` check (parent_node_id <> node_id)
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)
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So check constraint here is not allowed anymore.
Can you suggest any workaround besides having separate table for "relations" between nodes?
because of the way auto-increment columns are implemented, neither check constraints, nor virtual columns, not default expressions work with them, unfortunately.
as a workaround you might try to use sequences, perhaps they'll help.
Hi Sergei,
I've fixed the bug by disallowing auto-increment columns in CHECK constraints, DEFAULT value expressions and VIRTUAL COLUMN expressions, in commit https://github.com/MariaDB/server/commit/b7aa15458db95149af4f473a90009844a16e9db8. Please review.
Thanks,
Jacob