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To test any functionality in SQL Server, we need sample databases to test different scenarios. Few of the sample databases are already available as shown below and you can download and use for FREE.

1. AdventureWorks
2. WideWorldImporters
3. Northwind
4. Pubs

Sometimes, we need a customized sample table to test one of the SQL Server features. In such cases, above mentioned sample databases are not enough. So we need to create our own test table with some data too. Since there was no proper function available to generate a sample table in earlier version of SQL Server (before 2022), we used CAST(), RAND() and many other functions to achieve it somehow.

In SQL Server 2022, a new function came called GENERATE_SERIES(), which was a long awaited function. One of the usages of this function is that it can easily generate sample table having as much data as we want.

Compatibility Level:

Your database compatibility level MUST be 160 or higher to use this function. Given below is the query to change your database compatibility level.

ALTER DATABASE tempdb SET COMPATIBILITY_LEVEL = 160

Let me show you in the below example, how can we use GENERATE_SERIES() function to generate sample table in SQL Server 2022.

Example :

USE tempdb
GO

CREATE TABLE [Customers]
(
 [CustomerID]         INT,
 [CustomerName]       VARCHAR(250),
 [RegistrationDate]   DATE,
 [EmailAddress]       VARCHAR(100),
 [Address]            VARCHAR(500),
 [PhoneNumber]        VARCHAR(100),
 [DiscountPercentage] NUMERIC(18,6)
);
GO

DECLARE @Start INT = 1;    --Starting point of the record
DECLARE @Stop  INT = 1000; --Ending point of the record

INSERT INTO [Customers]
(
 [CustomerID],
 [CustomerName],
 [RegistrationDate],
 [EmailAddress],
 [Address],
 [PhoneNumber],
 [DiscountPercentage]
)

SELECT  
  value                                           AS [CustomerID]
, CONCAT('John',' - ',value)                      AS [CustomerName]
, DATEADD(day,value,'1753-01-01')                 AS [RegistrationDate]
, CONCAT('John',value,'@raresql.com')             AS [EmailAddress]
, CONCAT(value,' N. 10th Street')                 AS [Address]
, '1 (11) '+ RIGHT(CONCAT('0000000000',value),11) AS [PhoneNumber]
, CONVERT(NUMERIC(18,6),value)/@Stop              AS [DiscountPercentage]

FROM GENERATE_SERIES(@Start,@Stop);
GO

SELECT * FROM [Customers];
GO
--OUTPUT

Clean Up:

In order to clean up the table, we need to drop it as shown below.

USE DATABASE tempdb
GO

DROP Table [Customers];
GO

Conclusion:

I used GENERATE_SERIES() function to generate the sample table and I noticed that it has reduced a lot of complexity in creating sample table, compared to earlier approach. Do let me know if you have generated sample table and what was the approach.

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