1. 접속할 때 collation을 통일시키는 방법

$query = 'set session character_set_connection=utf8;';

mysql_query($query);

$query = 'set session character_set_client=utf8;';

mysql_query($query);

$query = 'set session character_set_results=utf8;';

mysql_query($query); $query = 'set collation_connection=utf8_general_ci;'; mysql_query($query);

즉 처음에 DB접속할 때 맞춰주는 것.... 

mysql 프롬프트 상에서는...

set session character_set_connection=utf8;

set session character_set_client=utf8;

set session character_set_results=utf8;

set collation_connection=utf8_general_ci;

2. 테이블을 변경시키는 방법

ALTER TABLE tbl_A DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

     tbl_A의 기본 셋팅을 맞춰주는 것... 만일 필드를 수정해야 한다면 해당 필드의 collation을 변경해주면 됨

3. 비교하는 변수의 collation을 변경시키는 방법

SELECT * FROM tbl_A [utf8_general_ci] WHERE field_A = var_B [utf8_unicode_ci]?

를 돌려야 하는 상황이라고 가정하면...

var_B의 collation을 변경시켜서 utf8_general_ci 로 바꿔주면 된다.

SELECT * FROM tbl_A (utf8_general_ci) WHERE field_A = var_B COLLATE utf8_general_ci ;