Illegal mix Mysql caused coding of collations (utf8_unicode_ci, IMPLICIT) and (utf8_general_ci, IMPLICIT) Error

1. [Error After:]

• When mysql database to perform multi-table join query:

select * from A LEFT JOIN B ON A.user_id = b.user_id

• An error occurred:

Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT)

That is probably inconsistent with encoding means encoding format of Table A and Table B can not be compared.

2. [Solution:]

• The Table A and Table B ( collationsor 校对规则encoded) unified manner utf8_general_ci

• Then execute the following statement:

  ```mysql

  alter table 表名convert to character set utf8 collate utf8_general_ci

```

note! ! !

This is generally done above step does not solve the problem, because the table inside the data before inserting it into, naturally before encoding utf8_unicode_ci, so make the time to compare data is still being given! ! ! To solve the problem: also need to continue the implementation of the second step, the encoding rules are also unified data table correct them

(Also, note: the difference between utf8_general_ci and utf8_unicode_ci, the former fast calibration speed, but somewhat less accurate; the latter high accuracy, but the calibration slower.)