Mysql不同字符串格式的连表查询

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

主要是连表查询的时候，=左边的字段为utf8_general_ci，右边的字段为utf8_general_ci，就会导致这种问题，解决方法是，把=两边的字段都变成同一种格式，再连表查询

select * from PackageInfo where Track COLLATE utf8_unicode_ci in( 

select Tracking COLLATE utf8_unicode_ci from PushToTrackSupplierInfo where Tracking = '1234567890')