# Sql issue with collation change

**URL:** <https://forums.percona.com/t/sql-issue-with-collation-change/30720>\
**Category:** MySQL & MariaDB\
**Created:** [May 30, 2024, 5:57pm UTC](https://forums.percona.com/t/sql-issue-with-collation-change/30720 "2024-05-30T17:57:25Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mmayantz](https://avatars.discourse-cdn.com/v4/letter/m/d26b3c/32.png) [@mmayantz](https://forums.percona.com/u/mmayantz)\
**Post date:** [May 30, 2024, 5:57pm UTC](https://forums.percona.com/t/sql-issue-with-collation-change/30720/1 "2024-05-30T17:57:25Z")

</div>

When i tried to apply: character set utf8mb4 collate utf8mb4\_unicode\_ci,

it pops with this error:

2024-05-29T13:48:59 Error copying rows from `schema`.`table_name` to `schema`.`_table_name_new`: 2024-05-29T13:48:59 Copying rows caused a MySQL error 1300:  
Level: Warning  
Code: 1300  
Message: Invalid utf8mb4 character string: ‘A4F64D’

This ONLY happens when the field im modifying is of type utf8\_unicode\_ci…i.e.: upgrading to utf8mb4 seems to not work. I can confirm that all the rows being copied over have no bizarre characters in them…

---

<div class="post-metadata">

**Author:** ![yunus.uyanik](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/yunus.uyanik/32/19250_2.png) [@yunus.uyanik](https://forums.percona.com/u/yunus.uyanik)\
**Post date:** [June 6, 2024, 2:53pm UTC](https://forums.percona.com/t/sql-issue-with-collation-change/30720/2 "2024-06-06T14:53:50Z")

</div>

Hi @mmayantz  
As an idea, have you found that row and fully checked it?

These kinds of errors are mostly related to the data, but if you can provide your table structure and syntax while using schema changes, we can have a better idea of it.

Please be aware this is a public website, and make sure to apply reduction on your field and table names and so on.