Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation =

執行SQL查詢時,報:Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation = “”
原因:關聯字段編碼不一致

解決:檢查次查詢中,關聯字段的編碼

小技巧:
執行此SQL可查詢字符集編碼不一致問題

修正字符集SQL
SELECT TABLE_SCHEMA '數據庫',TABLE_NAME '表',COLUMN_NAME '字段',CHARACTER_SET_NAME '原字符集',COLLATION_NAME '原排序規則',CONCAT('ALTER TABLE ', TABLE_SCHEMA,'.',TABLE_NAME, ' MODIFY COLUMN ',COLUMN_NAME,' ',COLUMN_TYPE,' CHARACTER SET utf8 COLLATE utf8_unicode_ci;') '修正SQL'
FROM information_schema.`COLUMNS` 
WHERE COLLATION_NAME RLIKE 'utf8_general_ci' and table_schema='test'