aws aurora rds (mysql) in a cluster cannot insert emoji - mysql

Question

I am using an aurora rds (mysql) in a cluster and cannot insert emoji's. The column which I am trying to insert into has the collation:
utf8mb4 - utf8mb4_unicode_ci
I have tried inserting using client and also from mysql workbench writing the query but in both cases I just see ???? in the field.
I have updated the table default character set:
utf8mb4
and default collation:
utf8mb4_unicode_ci
But still getting ??? instead of emoji
Edit 1:
I've tried to edit the parameter group of the cluster and set all character set values to utf8mb4 and all collation values to utf8mb4_unicode_ci but still not working.

Answer 1

Your cluster parameter group should have the following options set:
character_set_client: utf8mb4
character_set_connection: utf8mb4
character_set_database: utf8mb4
character_set_server: utf8mb4
collation_connection: utf8mb4_unicode_ci
collation_server: utf8mb4_unicode_ci
Rebooting your instances after updating this might be required. When you connect to the cluster you want to set the correct collation for your connection, like this:
SET NAMES utf8mb4 COLLATE utf8mb4_unicode_ci;
If you run SHOW VARIABLES LIKE "%collation%" after this you should see three variables that all have the correct collation (utf8mb4_unicode_ci).
You also need to convert your tables and columns to the correct charset and collation, this has been answered before on the DBA Stack Exchange: How to easily convert utf8 tables to utf8mb4 in MySQL 5.5

Answer 2

Changing the default character set of a table doesn't alter any of the existing columns. You can run SHOW CREATE TABLE MyTable and see the difference.
For example, we can create a table with an old-fashioned charset:
mysql> create table MyTable (string1 varchar(100) ) default character set = latin1;
mysql> show create table MyTable\G
*************************** 1. row ***************************
Table: MyTable
Create Table: CREATE TABLE `MyTable` (
`string1` varchar(100) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
Next, we change the table's default, but we see that does not change the column. The existing column automatically gets an option showing us what it actually uses for a charset, since it's now different from the table default:
mysql> alter table MyTable default charset = utf8mb4;
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table MyTable\G
*************************** 1. row ***************************
Table: MyTable
Create Table: CREATE TABLE `MyTable` (
`string1` varchar(100) CHARACTER SET latin1 DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
1 row in set (0.00 sec)
The default is used for columns added to the table subsequently:
mysql> alter table MyTable add column string2 varchar(100);
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table MyTable\G
*************************** 1. row ***************************
Table: MyTable
Create Table: CREATE TABLE `MyTable` (
`string1` varchar(100) CHARACTER SET latin1 DEFAULT NULL,
`string2` varchar(100) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
To convert the existing column, use CONVERT TO CHARACTER SET. This rewrites the table, converting the existing data of each column if needed:
mysql> alter table MyTable convert to character set utf8mb4;
Query OK, 0 rows affected (0.09 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table MyTable\G
*************************** 1. row ***************************
Table: MyTable
Create Table: CREATE TABLE `MyTable` (
`string1` varchar(100) DEFAULT NULL,
`string2` varchar(100) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
Now both columns say nothing about their respective charsets, because they match the table's default.

Answer 3

I wrote a detailed blog post (a few years back) explaining how to support emoji and Aurora MySQL in Ruby on Rails here:
https://josephecombs.com/2018/05/06/how-to-support-emojis-with-rails-elasticbeanstalk-and-amazon-aurora
I know external links are frowned upon here, but this could help others in a similar situation. The guide is too long to paste as an answer.