The comparison between json and binary is different from MySQL

[tangenta]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table if exists t1, t2;
create table t1 (a binary(13));
insert into t1 values('');
create table t2 (a json);
insert into t2 values ('"str"');
select * from t1 join t2 on t1.a <= t2.a;

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

MySQL(5.7 && 8.0):

Empty set (0.03 sec)

3. What did you see instead (Required)

+---------------+-------+
| a             | a     |
+---------------+-------+
|               | "str" |
+---------------+-------+
1 row in set (0.01 sec)

4. What is your TiDB version? (Required)

afa1335