What is the function to find length in mysql?

Mysql's function to find the length is the length() function and the char_length() function; the length() function can return the length of the string in bytes, and the char_length() function can return the length in characters. The length of the string in units.

Both the char_length function and the length function in MySQL can return the length of the string

mysql> select length('MySQL'), char_length('MySQL'); +-----------------+----------------------+ | length('MySQL') | char_length('MySQL') | +-----------------+----------------------+ | 5 | 5 | +-----------------+----------------------+ 1 row in set (0.01 sec)

The functions of the two functions:

• LENGTH() Returns the length of a string in bytes.

• CHAR_LENGTH() Returns the length of a string in characters.

Judging from the above example, "MySQL" has a total of 5 characters, and each character should occupy 1 byte.

But Chinese is different. Generally, one Chinese character occupies 2-3 bytes. For example:

GBK character set encoding:

select char_length(‘中国’); // 2个字符 select length(‘中国’); // 4个字节，一个汉字2个字节 select bit_length(‘中国’); // 32位。4*8 = 32

UTF8 character set encoding:

select char_length(‘中国’);// 2个字符 select length(‘中国’); // 6个字节，一个汉字3个字节 select bit_length(‘中国’); // 48位。6*8 = 48

Summary

char_length(str )

• The unit of length is characters, a multi-byte character is counted as a single character

• It does not matter whether it is Chinese characters, numbers or letters. One character

length(str)

• Under utf8 encoding, one Chinese character counts as three characters, and one number or letter counts as one character.

• Under other encodings, one Chinese character counts as two characters, and one number or letter counts as one character.

Recommended tutorial:mysql video tutorial

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