Managing String Content in View Definitions

The hidden text (this_is_hidden_text_in_the_view) in the view definition is an intriguing addition. Anything after the SELECT * FROM sys.tables query that is not a valid SQL statement (like a comment or plain text) will not be executed or parsed by SQL Server. It essentially becomes invisible to the engine and is purely for informational or decorative purposes within the script.

CREATE OR ALTER VIEW dbo.SampleView
AS
	SELECT	* FROM sys.tables

	this_is_hidden_text_in_the_view

GO

In the medata you will see:

SELECT * FROM sys.[sql_modules] WHERE [definition] LIKE '%hidden_tex%'

Storing free text that isn’t a valid T-SQL statement within a view definition can indeed break code consistency rules and potentially lead to confusions in database management and development. Here are several key points to explain this concern:

1. Code Consistency: Views in SQL Server are designed to encapsulate logical queries that retrieve and present data in a structured manner. They should adhere to standard SQL syntax and maintain a clear purpose. Introducing free text that isn’t part of a valid SQL statement contradicts this principle of consistency. It blurs the line between executable code and documentation, potentially making it harder for developers to understand and maintain the view over time.
2. Parsing and Execution: SQL Server parses and executes the view definition to retrieve data when the view is queried. Any non-SQL text included in the view definition, such as comments or free text, is ignored during this process. While this doesn’t affect the functionality of the view directly, it can mislead developers who might expect the free text to behave as part of the SQL logic.
3. Maintenance Challenges: Over time, as views are updated or modified, the non-SQL text within their definitions may become outdated or irrelevant. This can confuse developers who rely on accurate documentation embedded within the code. It also creates maintenance challenges, as developers might overlook or misinterpret the purpose of the non-SQL text during updates.
4. Communication and Collaboration: In collaborative environments, adhering to consistent coding practices ensures that all team members can easily understand and work with database objects. Non-standard practices like embedding free text in view definitions can hinder effective communication about the view’s purpose, leading to misunderstandings or errors in development and maintenance tasks.
5. Documentation Separation: Best practices advocate for separating documentation from executable code. While comments within SQL code (using /* */ or --) are valid and beneficial for documenting SQL logic, embedding free text directly within view definitions blurs this distinction. It introduces content that isn’t intended for execution but might be mistakenly interpreted as such.
6. Risk of Misinterpretation: Developers unfamiliar with the database might misinterpret non-SQL text within view definitions as part of the SQL logic. This misunderstanding can lead to incorrect assumptions about the functionality or design intent of the view, potentially causing errors or inefficiencies in application development.

Conclusion

In conclusion, while adding non-SQL free text to view definitions might seem convenient for documentation purposes, it poses risks to code consistency and clarity in SQL Server development. It’s advisable to adhere to established coding standards and separate documentation from executable code to maintain transparency, facilitate maintenance, and mitigate confusion among developers working with database objects. Clear communication and consistent practices are key to ensuring the reliability and manageability of database systems over time.