替换中文后操作 'concat' 的归类非法混合

Question

Before:

set extrainfo =concat('{"from":"carpool","table":"Block",  
"key_field":"b_index","key_value:"',b_index,'","infoid":"',info_id,'",
"code":"0","message":"This trip is valid"}');

运行 success. I replaced "This trip is valid" with "行程符合规范" :

set extrainfo =concat( '{"from":"carpool","table":"Block","key_field":
"b_index","key_value:"',b_index,'","infoid":"',info_id,'",
"code":"0","message":"行程符合规范"}');

show me:

(node:30849) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): 
`enter code here`Error: ER_CANT_AGGREGATE_NCOLLATIONS: 
`enter code here`Illegal mix of collations for operation 'concat'

Can you help me?

Answer 1

我更改了代码：

set extrainfo =concat( '{"from":"carpool","table":"Block","key_field":
   "b_index","key_value:"',convert(b_index,char),'","infoid":"',convert(info_id,char),'",
"code":"0","message":"行程符合规范"}');

将 b_index 替换为 convert(b_index,char)。效果不错。

替换中文后操作 'concat' 的归类非法混合

Illegal mix of collations for operation 'concat' after replace chinese

mysql

concat

utf-8