utf8mb3:阉割过的utf8字符集,只使用1～3个字节表示字符 utf8mb4:正宗的utf8字符集,使用1～4个字节表示字符 比较规则 MySQL版本一共支持41种字符集,其中的Default collation列表示这种字符集中一种默认的比较规则,里面包含着该比较规则主要作用于哪种语言,比如utf8_polish_ci表示以波兰语的规则比较,utf8_spanish...
character set utf8mb3 指的是一种字符集,用于定义数据库中存储和检索字符数据的方式。utf8mb3 是MySQL 中的一个字符集,它是 UTF-8 字符集的一个子集,支持最多三个字节的字符编码,能够表示大多数常用的 Unicode 字符,但不支持所有 Unicode 字符(例如,某些表情符号)。 2. collate utf8mb3_general_ci的含义和...
CREATE TABLE t (s1 CHAR(1)) CHARACTER SET utf8mb3; SELECT * FROM t WHERE s1 COLLATE utf8mb3_general_ci = 'x'; DECLARE x VARCHAR(5) CHARACTER SET utf8mb3 COLLATE utf8mb3_danish_ci; SELECT CAST('a' AS CHAR CHARACTER SET utf8mb4) COLLATE utf8mb4_czech_ci; Prior to MySQL 8.0....
utf8is an alias forutf8mb3; the character limit is implicit, rather than explicit in the name. utf8mb3can be used inCHARACTER SETclauses, andutf8mb3_collation_substringinCOLLATEclauses, wherecollation_substringisbin,czech_ci,danish_ci,esperanto_ci,estonian_ci, and so forth. For example: ...
重点结论:司内建表 字符集 CHARSET=utf8mb4,排序规则 COLLATE=utf8mb4_bin 前言 近期由于项目迭代,做了一些新建数据模型的表的操作,发现在测试环境的MySQL数据库中,建表规范形态各异,也去参看了下司内DBA的规范,一些规范还是有的,只是各团队执行情况各异,由此引入一些不必要的问题,本篇单对字符集、排序规则做...
CREATE TABLE t1 ( col1 CHAR(10) CHARACTER SET utf8mb3 COLLATE utf8mb3_unicode_ci NOT NULL, col2 CHAR(10) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin NOT NULL ) CHARACTER SET utf8mb3; The following statement converts t1 to use utf8mb4: ...
最后,我们需要逐表将字符集从utf8mb3改为utf8mb4。首先,列出所有表: #列出所有表SHOW TABLES; 1. 2. 然后逐表执行以下代码修改字符集: #修改表的字符集ALTER TABLE 表名 CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; 1.
System.NotSupportedException: Character set 'utf8mb3' is not supported by .Net Framework, Power BI Desktop: Refresh data error 'Character set 'utf8mb3' is not supported, MySQL server has gone away due to error CHARACTER SET 'utf8'
Column Character Set Conversion 这节记住语法即可:ALTER TABLE t MODIFY col CHAR(50) CHARACTER SET utf8mb4 COLLATE utf8_general_ci; Collation Issues Using COLLATE in SQL Statements 在ORDER BY/AS/ GROUP BY/DISTINCT/WHERE/HAVING/聚合函数中,都可以跟上COLLATE xxx,例如: ...
Examples when setting @@character_set_client and @@character_set_connection to different values can be useful: Example 1: Suppose, we have a utf8 database with this table: CREATE TABLE t1 (a VARCHAR(10)) CHARACTER SET utf8 COLLATE utf8_general_ci; INSERT INTO t1 VALUES ('oe'),('ö...