MySQL length function number small problem

The length function can test for character lengths in the specified field, but some attentive friends will find that the length function is different from the lengths of the coded tests.

Utf-8: Length () 3 lengths of a Chinese character

Gbk:length () 2 length of a Chinese character

Attention:

Length: is a calculation of the lengths of a field a Chinese character is counted three characters, a number or letter is counted as a character

Char_length: Whether Chinese characters or numbers or letters is a character

To sum up, if you want to be able to use the Char_length function, no matter what it is uniformly calculated.