Generate a resultset of incrementing dates in T-SQL

Optimize your date generation: Additional techniques

The straightforward recursive CTE method is quite efficient, but depending upon your requirements, there might be cases which demand alternative techniques. System limitations and SQL Server version specificity also play a significant role here.

Quick trick with the master database

The master.dbo.spt_values table can be a handy tool. It can easily generate numbers which can be transformed into dates:

SELECT TOP (DATEDIFF(DAY, @StartDate, @EndDate) + 1)
  DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) - 1, @StartDate) AS DateValue
FROM master.dbo.spt_values
WHERE type = 'P' AND number <= DATEDIFF(DAY, @StartDate, @EndDate)
/* Who knew databases could do magic? */


Don't forget that this method has constraints — the master.dbo.spt_values table contains a limited number of rows, capping the range to 2047 days.

Set-based solutions using a tally table

A tally table or a numbers table, can provide another path to well-performing date sequences:

;WITH Nums AS (
    SELECT row_number() OVER (ORDER BY (SELECT NULL)) as n
    FROM master..spt_values
)
SELECT TOP (DATEDIFF(DAY, @StartDate, @EndDate) + 1)
    DATEADD(DAY, n - 1, @StartDate) as DateValue
FROM Nums
ORDER BY n
/* More like a tally of my procrastination during debugging! */


This illustrates the power of set-based solutions, which can bring significant performance benefits over loops due the inherent optimization of SQL Server.

SQL Server version compatibility

Putting a clear tag on solutions that depend on features specific to newer SQL Server versions can save your team (or future you) a lot of debugging time. Compatibility testing beforehand is a must, folks.

Avoiding endless recursion in recursive CTEs

Whenever crafting recursive CTEs, ensure to include a termination clause in your WHERE condition. It's like the emergency break to put a stop to any potential infinite loop. Don't let your server feel infinite regret for allowing endless recursion!

Diving deeper: Robust solutions for diverse scenarios

Let's delve into more aspects for building robust queries for incrementing dates, keeping in view performance, future adaptations and potential pitfalls.

Handling extensive date ranges

For large date ranges, evaluate the performance implications by testing against large datasets. Using temporary tables might be tempting, but don't overlook permanent tables for recurrent operations.

The power of Common Table Expressions

Common Table Expressions or CTEs are a powerful tool in your arsenal. They can simplify complex queries, enhance readability, and reduce dependency on temporary tables.

Efficient date list generation

For frequent date list generation, consider capturing dates into a permanent table. Querying a static date set can prove to be much more efficient than dynamic generation.

Server functionality investigation

Examining underneath the hood can be fruitful. Comprehending the underlying SQL Server functionality when using system tables or functions can avoid potential issues introduced by version changes.