mysql 字符集错误 Illegal mix of collations

  SELECT * FROM     mobile_card.mcc_o2o_repayment_request orr         INNER JOIN     bi_o2o_sfq.CARD C ON C.CARDID = orr.cardno LIMIT 0, 50

Error Code: 1267. Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '=' 0.038 sec

这个是Mysql字符集错误

SELECT *

FROM

    mobile_card.mcc_o2o_repayment_request orr

        INNER JOIN

    bi_o2o_sfq.CARD C ON C.CARDID = orr.cardno COLLATE utf8_unicode_ci

给错误的字符集合，给强制转化一下  加   COLLATE utf8_unicode_ci