How to count the number of Chinese characters in a field in data (ORACLE)

How to count the number of Chinese characters in a field in data (ORACLE)
How to count the number of Chinese characters in a field in the data table www.2cto.com dept has the following data:
In Oracle, length is the length of characters, lengthb is the length of bytes, and a Chinese character is two bytes, numbers, letters, punctuation and so on.
Www.2cto.com select lengthb (DNAME) from dept ;--
Select LENGTH (DNAME) from dept;

-- Count the number of Chinese characters in the DNAME field select lengthb (DNAME)-length (DNAME) from dept;