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關於MYSQL字符集問題(二)

查看 cti 總結 service jdbc連接 cli 如果 tar 準備

1.查看默認字符集(默認情況下,mysql的字符集是latin1(ISO_8859_1)
  通常,查看系統的字符集和排序方式的設定可以通過下面的兩條命令:
     mysql> SHOW VARIABLES LIKE character%;
+--------------------------+---------------------------------+
| Variable_name            | Value                           |
+--------------------------+---------------------------------+
| character_set_client | latin1 | | character_set_connection | latin1 | | character_set_database | latin1 | | character_set_filesystem | binary | | character_set_results | latin1 |
| character_set_server | latin1 | | character_set_system | utf8 | | character_sets_dir | D:"mysql-5.0.37"share"charsets" | +--------------------------+---------------------------------+ mysql> SHOW VARIABLES LIKE collation_%;
+----------------------+-----------------+ | Variable_name | Value | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database | utf8_general_ci | | collation_server | utf8_general_ci | +----------------------+-----------------+

2.修改默認字符集
  (1) 最簡單的修改方法,就是修改mysql的my.ini文件中的字符集鍵值,如:
default-character-set = utf8
character_set_server =  utf8
   修改完後,重啟mysql的服務,service mysql restart
   使用 mysql> SHOW VARIABLES LIKE ‘character%‘;查看,發現數據庫編碼均已改成utf8
+--------------------------+---------------------------------+
| Variable_name            | Value                           |
+--------------------------+---------------------------------+
| character_set_client     | utf8                            |
| character_set_connection | utf8                            |
| character_set_database   | utf8                            |
| character_set_filesystem | binary                          |
| character_set_results    | utf8                            |
| character_set_server     | utf8                            |
| character_set_system     | utf8                            |
| character_sets_dir       | D:"mysql-5.0.37"share"charsets" |
+--------------------------+---------------------------------+
   (2) 還有一種修改字符集的方法,就是使用mysql的命令
mysql> SET character_set_client = utf8 ;
mysql> SET character_set_connection = utf8 ;
mysql> SET character_set_database = utf8 ;
mysql> SET character_set_results = utf8 ;
mysql> SET character_set_server = utf8 ;

mysql> SET collation_connection = utf8 ;
mysql> SET collation_database = utf8 ;
mysql> SET collation_server = utf8 ;
  一般就算設置了表的默認字符集為utf8並且通過UTF-8編碼發送查詢,你會發現存入數據庫的仍然是亂碼。問題就出在這個connection連接層上。解決方法是在發送查詢前執行一下下面這句:
SET NAMES utf8;
它相當於下面的三句指令:
SET character_set_client = utf8;
SET character_set_results = utf8;
SET character_set_connection = utf8;
總結: 
因此,使用什麽數據庫版本,不管是3.x,還是4.0.x還是4.1.x,其實對我們來說不重要,重要的有二: 
  1) 正確的設定數據庫編碼.MySQL4.0以下版本的字符集總是默認ISO8859-1,MySQL4.1在安裝的時候會讓你選擇。如果你準備使用UTF- 8,那麽在創建數據庫的時候就要指定好UTF-8(創建好以後也可以改,4.1以上版本還可以單獨指定表的字符集) 
  2) 正確的設定數據庫connection編碼.設置好數據庫的編碼後,在連接數據庫時候,應該指定connection的編碼,比如使用jdbc連接時,指定連接為utf8方式.

關於MYSQL字符集問題(二)