MySql 5.7 Fungsi UUID() default collation - Campuran ilegal collation

(Ini sebenarnya bukan jawaban, tetapi upaya untuk mengisolasi apa yang menyebabkan masalah dan apa yang mungkin memperbaikinya.)

Masuk ke DATABASE dengan CHARACTER SET yang sama sekali tidak relevan dan COLLATION .

mysql> CREATE DATABASE `so40064402` /*!40100 DEFAULT CHARACTER SET ucs2 COLLATE ucs2_bin */
mysql> USE so40064402;
Database changed

Tetapkan utf8_polish untuk klien:

mysql> SET NAMES utf8 COLLATE utf8_polish_ci;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'c%a%t%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       | -- from SET NAMES
| character_set_connection | utf8                       | -- from SET NAMES
| character_set_database   | ucs2                       | -- from DATABASE
| character_set_filesystem | binary                     | -- (constant)
| character_set_results    | utf8                       | -- from SET NAMES
| character_set_server     | utf8mb4                    |
| character_set_system     | utf8                       | -- (constant)
| character_sets_dir       | /usr/share/mysql/charsets/ |
| collation_connection     | utf8_polish_ci             | -- from SET NAMES
| collation_database       | ucs2_bin                   | -- from DATABASE
| collation_server         | utf8mb4_unicode_520_ci     |
+--------------------------+----------------------------+
11 rows in set (0.00 sec)

mysql> select charset(uuid()), collation(uuid());
+-----------------+-------------------+
| charset(uuid()) | collation(uuid()) |
+-----------------+-------------------+
| utf8            | utf8_general_ci   |  -- part of the problem, but can't fix this
+-----------------+-------------------+
1 row in set (0.00 sec)

mysql> select replace(uuid(),'-','');
ERROR 1270 (HY000): Illegal mix of collations
                 (utf8_general_ci,COERCIBLE),
                 (utf8_polish_ci,COERCIBLE),
                 (utf8_polish_ci,COERCIBLE) for operation 'replace'
mysql> 
mysql> 
mysql> 
mysql> SET NAMES utf8mb4 COLLATE utf8mb4_polish_ci;
Query OK, 0 rows affected (0.00 sec)

Sekarang mari kita ubah SET NAMES hanya. Sekarang berhasil!?? Terlepas dari UUID() menjadi utf8 !?

mysql> SHOW VARIABLES LIKE 'c%a%t%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8mb4                    | -- from SET NAMES
| character_set_connection | utf8mb4                    | -- from SET NAMES
| character_set_database   | ucs2                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8mb4                    | -- from SET NAMES
| character_set_server     | utf8mb4                    |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
| collation_connection     | utf8mb4_polish_ci          | -- from SET NAMES
| collation_database       | ucs2_bin                   |
| collation_server         | utf8mb4_unicode_520_ci     |
+--------------------------+----------------------------+
11 rows in set (0.00 sec)

mysql> select replace(uuid(),'-','');
+----------------------------------+
| replace(uuid(),'-','')           |
+----------------------------------+
| ea841aacf83b11e8a66580fa5b3669ce |
+----------------------------------+
1 row in set (0.00 sec)

mysql>