php+mysql保存emoji表情

解决方案参考：点击打开链接https://segmentfault.com/q/1010000003711491/a-1020000003712160

给一个标准的解决方案：

1. mysql的版本必须为v5.5.3或更高

2. 把数据库的编码改成utf8mb4 -- UTF-8 Unicode

3. 然后需要存储emoji表情的字段选择utf8mb4_general_ci

4. 数据库连接也需要改为utf8mb4

设置完成后，应该可以看到如下类似字符集设置结果。那么可以直接的存入数据库，无需做任何额外的事情了。

mysql> SHOW VARIABLES WHERE Variable_name LIKE "character\_set\_%" OR Variable_name LIKE "collation%";  
+--------------------------+--------------------+  
| Variable_name            | Value              |  
+--------------------------+--------------------+  
| character_set_client     | utf8mb4            |  
| character_set_connection | utf8mb4            |  
| character_set_database   | utf8mb4            |  
| character_set_filesystem | binary             |  
| character_set_results    | utf8mb4            |  
| character_set_server     | utf8mb4            |  
| character_set_system     | utf8               |  
| collation_connection     | utf8mb4_unicode_ci |  
| collation_database       | utf8mb4_unicode_ci |  
| collation_server         | utf8mb4_unicode_ci |  
+--------------------------+--------------------+  
 rows in set (0.00 sec)