The truncate error message is not compatible with MySQL when modifying the column type

[zimulala]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t(a char(250));
insert into t values("0123456789abc");
alter table t modify a char(12) null;

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

ERROR 1265 (01000): Data truncated for column 'a' at row 1

3. What did you see instead (Required)

ERROR 1406 (22001): Data Too Long, field len 12, data len 20

4. What is your TiDB version? (Required)

Release Version: v4.0.0-beta.2-2810-g3e0947fd2
Edition: Community
Git Commit Hash: 3e0947f
Git Branch: master

[zhaoxugang]

/assign

[zhaoxugang]

In my option， maybe like 'ERROR 1265 (01000 ) : Data truncated for column 'a ' , value is '0123456789abc' ' is enough , because the row num is not necessary and if get row num we will maintain a variable to record it .@zimulala

[zimulala]

@zhaoxugang
Well, I think so, in the reorg state, processing this number of rows is complicated and inaccurate

[ti-srebot]

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