为什么会出现此错误：此查询中操作“=”的排序规则 (utf8_general_ci,IMPLICIT) 和 (utf8_bin,NONE) 的非法混合？

Question

询问：

select *,
       (@page_path = concat(
           @page_path,
           chk_v_application_tree.alias
       )) as path
from chk_v_application_tree 

[Err] 1267 - 操作“=”时非法混合排序规则 (utf8_general_ci,IMPLICIT) 和 (utf8_bin,NONE)

Answer 1

尝试：

select *,
       (@page_path = concat(
           CONVERT(@page_path USING utf8) COLLATE utf8_bin,
           chk_v_application_tree.alias
       )) as path
from chk_v_application_tree

因为您不能在 CONCAT 函数（如 CONCAT(utf8_general_ci, utf8_bin)）中混合字符集编码。