The Oracle PL/SQL NCHAR data type is used to store fixed-length Unicode character strings, where each character occupies two bytes of storage.
In PL/SQL, the NCHAR data type is represented as a string literal enclosed in single quotes with the prefix ‘N’.
For example, the following code snippet defines a variable of NCHAR data type:
DECLARE my_var NCHAR(10) := N'Hello'; BEGIN NULL; END;
In the above code, the variable “my_var” is defined as an NCHAR data type with a maximum length of 10 characters, and it is initialized with the Unicode string “Hello”.
The NCHAR data type is useful when working with non-ASCII characters, such as those used in languages like Chinese, Japanese, and Arabic, as it can handle the extended Unicode character set. This data type is particularly useful when working with databases that support multilingual data, as it allows you to store and manipulate data in a variety of languages.
The NCHAR data type is also used for comparing and sorting Unicode strings. When comparing two NCHAR values, PL/SQL considers the Unicode code points, which allows for accurate comparisons and sorting of multilingual data.
It’s worth noting that the NCHAR data type occupies twice as much storage space as the CHAR data type. Therefore, it’s essential to consider the storage requirements when using NCHAR in large-scale applications. Additionally, you may also need to consider the performance implications of using NCHAR when manipulating large volumes of data.
In conclusion, the NCHAR data type in Oracle PL/SQL is a useful data type for storing and manipulating Unicode strings, particularly for multilingual applications. It supports the extended Unicode character set and is used for comparing and sorting Unicode strings accurately. However, due to its storage requirements, it’s essential to consider the performance implications of using NCHAR in large-scale applications.