ERROR 1105 (HY000): runtime error: index out of range [0] with length 0

[jackysp]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table if not exists ast (i varchar(20));
create table if not exists acc (j varchar(20), k varchar(20), l varchar(20), m varchar(20));

explain with t as(
select i,
    (case
        when b.j = '20001' then b.l
        else b.k
    end) an
from
    ast a
inner join acc b on
(a.i = b.m)
and a.i = 'astp2019121731703151'),
t1 as (select i, group_concat(an order by an separator '; ') an from t group by i)
select * from t1;

2. What did you expect to see? (Required)

No error.

3. What did you see instead (Required)

Panicked.

4. What is your TiDB version? (Required)

= v6.5.3
Actually panic starts from v6.5.6, it returns an error [2024/01/02 20:39:19.509 +08:00] [WARN] [session.go:2207] ["compile SQL failed"] [conn=2199023255955] [error="Can't find column Column#31 in schema Column: [test.ast.i,test.acc.j,test.acc.k,test.acc.l] Unique key: []"] [SQL="explain with t as(\nselect i,\n (case\n when b.j = '20001' then b.l\n else b.k\n end) an\nfrom\n ast a\ninner join acc b on\n(a.i = b.m)\nand a.i = 'astp2019121731703151'),\nt1 as (select i, group_concat(an order by an separator '; ') an from t group by i)\nselect * from t1"] on v6.5.3

[kennedy8312]

/type regression

[kennedy8312]

Regression Analysis
PR caused this regression: 46419

[seiya-annie]

/found customer

[seiya-annie]

/found community

[hi-rustin]

A workaround:

WITH RECURSIVE t AS (
    SELECT a.i,
           CASE WHEN b.j = '20001' THEN b.l ELSE b.k END AS an,
           ROW_NUMBER() OVER (PARTITION BY a.i ORDER BY CASE WHEN b.j = '20001' THEN b.l ELSE b.k END) AS rn,
           (SELECT COUNT(*) FROM acc WHERE m = 'astp2019121731703151') AS total_count
    FROM ast a
    INNER JOIN acc b ON a.i = b.m
    WHERE a.i = 'astp2019121731703151'
),
t1 AS (
    SELECT i, an, rn, total_count, CAST(an AS CHAR(1000)) AS concatenated
    FROM t
    WHERE rn = 1
    UNION ALL
    SELECT t.i, t.an, t.rn, t.total_count, CONCAT(t1.concatenated, '; ', t.an)
    FROM t
    INNER JOIN t1 ON t.i = t1.i AND t.rn = t1.rn + 1
),
final AS (
    SELECT i, concatenated AS an
    FROM t1
    WHERE rn = total_count
)
SELECT * FROM final;