然而,mysql的utf8只存储最多3个字节per code point. 所以,utf8字符集不能存储所有的unicode code points. 只能从0x000 to 0xFFFF(叫做Basic Multilingual Plane:BMP) The character set named utf8 uses a maximum of three bytes per character and contains only BMP characters. As of MySQL 5.5.3, the u...
if语句判断是否为UTF8 BOM格式,如果是,我们就从文件的第3个字节开始读文件,以便避开BOM,然后就是转换,最后成功输出。 代码中“注意”那行打印出字节编码,可见,字符已被转换成2 Bytes per character的GBK编码格式。 结束语:这里只写了UTF8格式的,UTF16的道理也一样,只是UTF16的BOM只有两个字节,具体可见上面的BO...
The UTF-8 variable-bytes-per-character encoding which also can be auto-detected either by optional BOM or some specific byte combinations. In particular, for an English character subset, the UTF-8 encoded file looks exactly like old plain ASCII text. That’s why UTF-8 is so popular and th...
utf8mb4 和 utf8 比较 utf8mb4: A UTF-8 encoding of the Unicode character set using one to four bytes per character. utf8mb3: A UTF-8 encoding of the Unicode character set using one to three bytes per character. utf8: An alias forutfmb3. (https://dev.mysql.com/doc/ref... UTF...
先来看一段MySQL的官方文档: utf8mb4: A UTF-8 encoding of the Unicode character set using one to four bytes per character. 翻译(utf8mb4:Unicode字符集的UTF-8编码,每个字符使用1-4
10.1.10.6 The utf8mb4 Character Set (4-Byte UTF-8 Unicode Encoding) The character set named utf8 uses a maximum of three bytes per character and contains only BMP characters. As of MySQL 5.5.3, the utf8mb4 character set uses a maximum of four bytes per character supports supplemental ...
utf8mb3 uses a maximum of three bytes per character. utf8mb4 uses a maximum of four bytes per character. Note This discussion refers to the utf8mb3 and utf8mb4 character set names to be explicit about referring to 3-byte and 4-byte UTF-8 character set data. The exception is that in...
UTF-16 is better where ASCII is not predominant, since it uses 2 bytes per character, primarily. UTF-8 will start to use 3 or more bytes for the higher order characters where UTF-16 remains at just 2 bytes for most characters.
The character set named utf8 uses a maximum of three bytes per character and contains only BMP characters. The utf8mb4 character set uses a maximum of four bytes per character supports supplementary characters: For a BMP character, utf8 and utf8mb4 have identical storage characteristics: same...
When MySQL developers first tried UTF-8, with its back-in-the-day six bytes per character, they likely balked: a CHAR(1) column would take six bytes; a CHAR(2) column would take 12 bytes; and so on. Let’s be clear: that initial behavior, which was never released, wascorrect. It...