爲什麼會出現此錯誤：對此操作進行操作'='時排序規則（utf8_general_ci，IMPLICIT）和（utf8_bin，NONE）的非法混合？

Question

查詢：

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

[Err] 1267 - Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_bin,NONE) for operation '='

Answer 1

嘗試：

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

正如你可能不喜歡CONCAT（utf8_general_ci，utf8_bin）在CONCAT功能混合字符集編碼。