The Nvarchar data type is a data type in SQL Server that is used to store variable-length Unicode character data. It is similar to the Varchar data type, but it can store Unicode characters, which means it can support multiple languages and character sets.
Characteristics of Nvarchar Data Type
The Nvarchar data type has the following characteristics:
- Variable-length: The length of an Nvarchar column can be between 1 and 4,000 characters. Unlike the Char data type, which stores fixed-length character data, the Nvarchar data type only uses as much storage space as needed for the actual data.
- Unicode support: The Nvarchar data type supports Unicode characters, which means it can store text in various languages and character sets.
This makes it suitable for applications that require multilingual support.
- Storage size: Each character in an Nvarchar column requires two bytes of storage space. Therefore, an Nvarchar column with a length of 100 characters will use 200 bytes of storage.
Usage of Nvarchar Data Type
The Nvarchar data type is commonly used in database tables when there is a need to store text values that may contain non-English or special characters. It allows for flexibility in handling different languages and ensures that no information is lost due to character encoding issues.
Example:
To create a table with an Nvarchar column in SQL Server, you can use the following syntax:
CREATE TABLE MyTable (
ID INT PRIMARY KEY,
Name NVARCHAR(50)
);
In this example, we are creating a table called “MyTable” with two columns: “ID” of type INT and “Name” of type Nvarchar. The “Name” column can store Unicode text up to 50 characters in length.
Difference between Nvarchar and Varchar
The main difference between the Nvarchar and Varchar data types is that the Nvarchar data type supports Unicode characters, while the Varchar data type does not. This means that Nvarchar can store text in multiple languages, while Varchar is limited to a specific character set, typically ASCII or ANSI.
Another difference is the storage size. As mentioned earlier, each character in an Nvarchar column requires two bytes of storage space, whereas each character in a Varchar column only requires one byte. Therefore, if storage space is a concern and you don’t need to support Unicode characters, using Varchar may be more efficient.
Conclusion
The Nvarchar data type is a versatile option for storing variable-length Unicode character data in SQL Server. It allows for the storage of text in multiple languages and character sets, making it suitable for international applications. Understanding the characteristics and differences between Nvarchar and other data types will help you make informed decisions when designing your database schema.