bug: COUNT(DISTINCT Multiple Expressions) syntax is not supported

davidshiz commented 1 year ago

Have you read the Contributing Guidelines on issues?

[X] I have read the Contributing Guidelines on issues.

Please confirm if bug report does NOT exists already ?

[X] I confirm there is no existing issue for this

Describe the problem

When more than one expression is provided in the DISTINCT clause， The COUNT(DISTINCT expression) syntax that is not supported by Tianmu engine.

mysql> select * from t1;
+------+------+------+
| idx  | c1   | c2   |
+------+------+------+
|    1 |    2 |    2 |
|    1 |    2 |    3 |
|    1 |    2 |    4 |
|    1 |    3 |    2 |
|    4 |    3 |    4 |
+------+------+------+
5 rows in set (0.00 sec)
mysql> select count(distinct c1,  c2)from t1;
ERROR 6 (HY000): The query includes syntax that is not supported by the storage engine. Either restructure the query with supported syntax, or enable the MySQL core::Query Path in config file to execute the query with reduced performance.

Expected behavior

mysql> select count(distinct c1,  c2)from t1;
+-------------------------+
| count(distinct c1,  c2) |
+-------------------------+
|                       5 |
+-------------------------+
1 row in set (0.00 sec)

How To Reproduce

CREATE TABLE `t1` (
  idx  int(11), 
  c1   int(11),
  c2   int(11)
);
insert into t1 values   (1, 2, 2), 
                        (1, 2, 3),
                        (1, 2, 4), 
                        (1, 3, 2), 
                        (4, 3, 4);
select count(distinct c1,  c2)from t1;

Environment

root@localhost:/# /stonedb57/install/bin/mysqld --version
/stonedb57/install/bin/mysqld  Ver 5.7.36-StoneDB for Linux on x86_64 (build-)
build information as follow:
        Repository address: https://github.com/stoneatom/stonedb.git:stonedb-5.7-dev
        Branch name: stonedb-5.7-dev
        Last commit ID: d0c2e01b6
        Last commit time: Date:   Wed Nov 2 19:58:00 2022 +0800
        Build time: Date: Sun 06 Nov 2022 08:50:06 AM UTC
root@ub01:~# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"

Are you interested in submitting a PR to solve the problem?

[ ] Yes, I will!

adofsauron commented 1 year ago

To demand development: https://github.com/stoneatom/stonedb/issues/954

RingsC commented 1 year ago

We will convert this issue from bug to a feature. @davidshiz