“Character set encoding basics Understanding character set encodings and legacy encodings” (http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&item_id=IWS-Chapter03) 注:原文链接已无法打开 Unicode Table:
character_set_connection:服务器处理请求时会把请求字符串从character_set_client所指定的字符集转为character_set_connection所指定的字符集 character_set_results:服务器向客户端返回结果时使用的字符集 故当系统变量character_set_client、character_set_results的设置与当前客户端使用的字符集不符时,很容易出现一些奇怪...
Q: What’s the algorithm to convert from UTF-16 to character codes? A: The Unicode Standard used to contain a short algorithm, now there is just a bit distribution table. Here are three short code snippets that translate the information from the bit distribution table into C code that will...
Because MySQL must allow for the worst case (that one character requires four bytes) the maximum length of autf16column or index is only half of the maximum length for aucs2column or index. For example, the maximum length of aMEMORYtable index key is 3072 bytes, so these statements create...
字节(Byte)是计量单位,表示数据量多少,是计算机信息技术用于计量存储容量的一种计量单位,通常情况下一字节等于八位。 字符(Character)计算机中使用的字母、数字、字和符号,比如'A'、'B'、'$'、'&',1、2、3、~!·#、￥、%、…、*、(、)—、+、'汉字'等等。
CREATE TABLE `user` ( `id` varchar(66) CHARACTER SET utf8mb4 NOT NULL, `name` varchar(33) CHARACTER SET utf8mb4 NOT NULL, `phone` varchar(33) CHARACTER SET utf8mb4 DEFAULT NULL, `password` varchar(100) CHARACTER SET utf8mb4 DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8; 当我...
CREATETABLEt1 ( col1CHAR(10)CHARACTERSETutf8COLLATEutf8_unicode_ciNOTNULL, col2CHAR(10)CHARACTERSETutf8COLLATEutf8_binNOTNULL )CHARACTERSETutf8; 下面的语句将t1转换为utf8mb4: ALTERTABLEt1 DEFAULTCHARACTERSETutf8mb4, MODIFYcol1CHAR(10)
altertable`table_name`modifyclo_namevarchar(20)charactersetutf8mb4;utf8 其实是 utf8mb3 的别名，...
character-set-server/default-character-set:服务器字符集,默认情况下所采用的。 character-set-database:数据库字符集。 character-set-table:数据库表字符集。 优先级依次增加。所以一般情况下只需要设置character-set-server,而在创建数据库和表时不特别指定字符集,这样统一采用character-set-server字符集。
From an UTF-16LE/BE string, compute the size of the UTF-8 equivalent string, From an UTF-32 string, compute the size of the UTF-8 or UTF-16LE equivalent string, From an UTF-16LE/BE string, compute the size of the UTF-32 equivalent string (equivalent to UTF-16 character counting)...