When Should You Use SQL Server's SYSNAME Data Type?

Understanding the SYSNAME Data Type in SQL Server

The SQL Server SYSNAME data type is specifically designed to store object names in table columns, variables, and stored procedure parameters. While the official documentation suggests this usage, it can be confusing to grasp the practical application.

Use Case for SYSNAME:

Imagine you have a stored procedure that creates a new table with a specified name. To ensure proper functionality, you need to pass the desired table name as a parameter to the stored procedure. Using SYSNAME as the data type for this parameter ensures that only valid object names are passed.

Comparison to NVARCHAR:

SYSNAME essentially behaves like an NVARCHAR(128) NOT NULL. Both can store up to 128 Unicode characters, but SYSNAME is always non-nullable. This inherent non-nullability makes it suitable for storing essential object names that cannot be left empty.

Additional Considerations:

• In earlier versions of SQL Server, SYSNAME was defined as VARCHAR(30).
• The exact definition of SYSNAME can vary across different instances of SQL Server.
• While SYSNAME is typically used for storing object names, it is not a common requirement in real-world scenarios.
• It is primarily used by Microsoft internally when creating system tables and stored procedures.

Conclusion:

The SYSNAME data type serves a specific purpose in SQL Server by ensuring that only valid object names are stored in relevant parameters and columns. Its use is limited but provides a level of data integrity and reliability when working with object names.

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