Differences between varchar2 and nvarchar2

VARCHAR2 (size) is a variable-length string. Its maximum length is size bytes. The maximum value of size is 4000, and the minimum value is 1. You must specify the size of a VARCHAR2.

NVARCHAR2 (size), a variable-length string. the maximum length of a string is size characters or bytes based on the selected national character set. The maximum size is determined by the number of bytes required for each character. The maximum size is 4000 bytes. You must specify a size for NVARCHAR2.

Differences:

1. When NVARCHAR2 (size is a character) Stores text in, one text is processed as one character

NVARCHAR2 (10) can contain 10 Chinese characters. If it is used to store English letters, it can only contain 10 characters.

NVarchar2 (size is a byte) can only contain 5 Chinese characters or English letters

2. VARCHAR2 contains two Chinese characters.

VARCHAR2 (10) can only contain 5 Chinese characters, and 10 Chinese characters (generally, GBK)