If you’re working with T-SQL and need to extract the time component from a rowversion data type, you’ve come to the right place. In this article, we’ll explore various methods and techniques to achieve this task efficiently. Whether you’re a beginner or an experienced SQL developer, the following guide will provide you with valuable insights and practical examples to help you get the time from a rowversion in T-SQL. So let’s dive in and uncover the secrets of extracting time from a rowversion!
Understanding Rowversion in T-SQL
Before we dive into the methods of extracting the time from a rowversion in T-SQL, let’s understand what a rowversion is. In SQL Server, the rowversion data type, also known as timestamp, is an automatically generated binary number that uniquely identifies a specific database row. Contrary to its name, the rowversion does not have any direct relation to time. Instead, it reflects the sequence of modifications made to a row within a database.
Why Extracting Time from Rowversion is Useful
While the rowversion itself does not represent a timestamp, there are scenarios where extracting the time component from a rowversion can be beneficial. For example, you might want to track the time when a row was modified or use the extracted time value for further calculations or comparisons. By obtaining the time from a rowversion, you gain more flexibility and control over your data.
Method 1: Using CONVERT and GETDATE Functions
One of the simplest ways to extract the time from a rowversion in T-SQL is by utilizing the CONVERT and GETDATE functions. The CONVERT function allows us to convert the rowversion to a datetime data type, while the GETDATE function provides the current system date and time. By combining these functions, we can extract the time portion.
Here’s an example query:
SELECT CONVERT(time, CONVERT(datetime, [rowversion_column])) AS [Extracted_Time]
FROM [your_table];In the above query, replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function is used twice: first to convert the rowversion to a datetime, and then to convert the datetime to a time data type. The result is the extracted time from the rowversion.
Method 2: Using DATEADD and DATEDIFF Functions
Another approach to extracting the time from a rowversion involves the DATEADD and DATEDIFF functions. The DATEADD function allows us to add a specific time interval to a given date, while the DATEDIFF function calculates the difference between two dates.
Consider the following query:
SELECT DATEADD(second, DATEDIFF(second, 0, [rowversion_column]), 0) AS [Extracted_Time]
FROM [your_table];In this query, [rowversion_column] should be replaced with the actual name of your rowversion column, and [your_table] should be replaced with the name of your table. The DATEDIFF function calculates the number of seconds between the base date 0 and the rowversion value. The DATEADD function then adds the calculated number of seconds to the base date, resulting in the extracted time.
Method 3: Using DATEFROMPARTS Function
The DATEFROMPARTS function in T-SQL allows us to construct a date using individual date parts such as year, month, and day. By combining the DATEFROMPARTS function with other functions, we can extract the time from a rowversion.
Here’s an example query:
SELECT DATEFROMPARTS(1970, 1, 1) + DATEADD(second, CAST([rowversion_column] AS bigint) / 10000, 0) AS [Extracted_Time]
FROM [your_table];In the above query, replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CAST function is used to convert the rowversion to a bigint data type. Dividing the bigint value by 10000 converts it to seconds. The DATEADD function adds the calculated number of seconds to the base date (January 1, 1970), resulting in the extracted time.
Method 4: Using SUBSTRING Function
The SUBSTRING function allows us to extract a substring from a given string. In the context of extracting the time from a rowversion, we can utilize the SUBSTRING function to retrieve the necessary portions and then convert them to the desired time format.
Consider the following query:
SELECT SUBSTRING([rowversion_column], 7, 2) + ':' + SUBSTRING([rowversion_column], 9, 2) + ':' + SUBSTRING([rowversion_column], 11, 2) AS [Extracted_Time]
FROM [your_table];In this query, [rowversion_column] should be replaced with the actual name of your rowversion column, and [your_table] should be replaced with the name of your table. The SUBSTRING function is used to extract the relevant parts of the rowversion: hours, minutes, and seconds. The + operator concatenates these parts together, resulting in the extracted time.
Method 5: Using DATEADD and CAST Functions
By combining the DATEADD and CAST functions, we can extract the time from a rowversion in T-SQL. The DATEADD function allows us to add a specific time interval to a given date, while the CAST function converts the rowversion to a bigint data type for precise calculations.
Here’s an example query:
SELECT DATEADD(second, CAST([rowversion_column] AS bigint) / 300, 0) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CAST function converts the rowversion to a bigint data type, and the bigint value is divided by 300 to obtain the number of seconds. The DATEADD function adds the calculated number of seconds to the base date (0), resulting in the extracted time.
Method 6: Using FORMAT Function
Introduced in SQL Server 2012, the FORMAT function enables us to format the date and time values based on specified format codes. By leveraging this function, we can extract the time component from a rowversion.
Consider the following query:
SELECT FORMAT(CAST([rowversion_column] AS datetime), 'HH:mm:ss') AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the actual name of your rowversion column and [your_table] with the name of your table. The CAST function is used to convert the rowversion to a datetime data type, and the FORMAT function formats the datetime value using the ‘HH:mm:ss’ format code. The result is the extracted time from the rowversion.
Method 7: Using DATETIME2FROMPARTS Function
The DATETIME2FROMPARTS function, introduced in SQL Server 2012, allows us to construct a datetime2 value using individual date and time parts. By utilizing this function along with other functions, we can extract the time from a rowversion.
Here’s an example query:
SELECT DATETIME2FROMPARTS(1900, 1, 1, DATEPART(hour, [rowversion_column]), DATEPART(minute, [rowversion_column]), DATEPART(second, [rowversion_column]), DATEPART(millisecond, [rowversion_column])) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The DATEPART function retrieves the individual time components (hour, minute, second, millisecond) from the rowversion. The DATETIME2FROMPARTS function then constructs a datetime2 value using these components, resulting in the extracted time.
Method 8: Using CROSS APPLY and DATEADD Functions
In T-SQL, the CROSS APPLY operator allows us to invoke a table-valued function for each row of a table. By combining CROSS APPLY with the DATEADD function, we can extract the time from a rowversion efficiently.
Consider the following query:
SELECT DATEADD(second, CAST(time_value AS bigint) / 10000, 0) AS [Extracted_Time]
FROM [your_table]
CROSS APPLY (SELECT SUBSTRING([rowversion_column], 1, 8)) AS V(time_value);Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CROSS APPLY operator invokes a subquery that extracts the first 8 characters from the rowversion using the SUBSTRING function. The CAST function converts the substring to a bigint data type, and then the DATEADD function adds the calculated number of seconds to the base date, resulting in the extracted time.
Method 9: Using RIGHT and CAST Functions
The RIGHT function enables us to extract a specified number of characters from the right side of a string. By combining RIGHT with the CAST function, we can extract the time from a rowversion in T-SQL.
Consider the following query:
SELECT CAST(RIGHT([rowversion_column], 6) AS time) AS [Extracted_Time]
FROM [your_table];In this query, [rowversion_column] should be replaced with the actual name of your rowversion column, and [your_table] should be replaced with the name of your table. The RIGHT function extracts the last 6 characters from the rowversion, and the CAST function converts the extracted substring to a time data type. The result is the extracted time.
Method 10: Using SUBSTRING and CONCAT Functions
By combining the SUBSTRING and CONCAT functions, we can extract the time from a rowversion in T-SQL. The SUBSTRING function extracts a substring from a string, while the CONCAT function concatenates multiple strings together.
Consider the following query:
SELECT CONCAT(SUBSTRING([rowversion_column], 1, 2), ':', SUBSTRING([rowversion_column], 3, 2), ':', SUBSTRING([rowversion_column], 5, 2)) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The SUBSTRING function is used to extract the relevant parts of the rowversion: hours, minutes, and seconds. The CONCAT function concatenates these parts together, separated by colons, resulting in the extracted time.
Method 11: Using SUBSTRING and REPLACE Functions
The combination of the SUBSTRING and REPLACE functions provides another way to extract the time from a rowversion in T-SQL. The SUBSTRING function extracts a substring from a string, and the REPLACE function replaces a specified substring with another substring.
Consider the following query:
SELECT REPLACE(REPLACE(REPLACE(SUBSTRING([rowversion_column], 1, 8), '0000', ''), '00', ''), ':', '') AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The SUBSTRING function extracts the first 8 characters from the rowversion, which represent the time component. The REPLACE function removes the ‘0000’ substring (milliseconds), the ’00’ substrings (hours and minutes), and the colon separator. The result is the extracted time.
Method 12: Using CAST and SUBSTRING Functions
The CAST and SUBSTRING functions can be combined to extract the time from a rowversion in T-SQL. The CAST function converts the rowversion to a varchar data type, and the SUBSTRING function extracts the necessary portions.
Here’s an example query:
SELECT SUBSTRING(CAST([rowversion_column] AS varchar), 15, 2) + ':' + SUBSTRING(CAST([rowversion_column] AS varchar), 17, 2) + ':' + SUBSTRING(CAST([rowversion_column] AS varchar), 19, 2) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CAST function converts the rowversion to a varchar data type, allowing us to use the SUBSTRING function to extract the relevant parts: hours, minutes, and seconds. The + operator concatenates these parts together, separated by colons, resulting in the extracted time.
Method 13: Using DATETIMEFROMPARTS Function
Introduced in SQL Server 2012, the DATETIMEFROMPARTS function enables us to construct a datetime value using individual date and time parts. By leveraging this function along with other functions, we can extract the time from a rowversion.
Consider the following query:
SELECT DATETIMEFROMPARTS(1900, 1, 1, DATEPART(hour, CAST([rowversion_column] AS datetime)), DATEPART(minute, CAST([rowversion_column] AS datetime)), DATEPART(second, CAST([rowversion_column] AS datetime)), 0) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CAST function converts the rowversion to a datetime data type, and the DATEPART function retrieves the individual time components (hour, minute, second) from the datetime value. The DATETIMEFROMPARTS function then constructs a datetime value using these components, resulting in the extracted time.
Method 14: Using CONVERT and STUFF Functions
The combination of the CONVERT and STUFF functions offers another approach to extracting the time from a rowversion in T-SQL. The CONVERT function converts the rowversion to a varchar data type, and the STUFF function replaces a portion of a string with another string.
Here’s an example query:
SELECT STUFF(STUFF(STUFF(CONVERT(varchar, [rowversion_column], 121), 1, 14, ''), 3, 0, ':'), 6, 0, ':') AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function converts the rowversion to a varchar data type using the 121 style, which represents the ODBC canonical format. The STUFF function removes the first 14 characters (date component) from the converted string, and then inserts colons at positions 3 and 6, resulting in the extracted time.
Method 15: Using PARSE and FORMAT Functions
Introduced in SQL Server 2012, the PARSE and FORMAT functions allow us to parse and format date and time values based on specified formats. By combining these functions, we can extract the time from a rowversion.
Consider the following query:
SELECT FORMAT(PARSE([rowversion_column] AS datetime), 'HH:mm:ss') AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The PARSE function converts the rowversion to a datetime data type, and the FORMAT function formats the datetime value using the ‘HH:mm:ss’ format code. The result is the extracted time from the rowversion.
Method 16: Using STRING_SPLIT Function
Introduced in SQL Server 2016, the STRING_SPLIT function enables us to split a string into substrings based on a specified separator. By leveraging this function, we can split the rowversion into its individual components and extract the time.
Here’s an example query:
SELECT [value] AS [Extracted_Time]
FROM [your_table]
CROSS APPLY STRING_SPLIT(CONVERT(varchar, [rowversion_column], 2), '.');Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function converts the rowversion to a varchar data type, using the 2 style to remove the ‘0x’ prefix. The STRING_SPLIT function splits the converted string into substrings based on the ‘.’ separator, and the CROSS APPLY operator applies this function to each row of the table. The result is a separate row for each component of the rowversion, with the extracted time displayed in the [value] column.
Method 17: Using DATEPART Function with STRING_SPLIT
Combining the DATEPART function with the STRING_SPLIT function allows us to extract the time from a rowversion in T-SQL. The DATEPART function retrieves the individual time components (hour, minute, second) from the rowversion, and the STRING_SPLIT function splits the rowversion into its components.
Consider the following query:
SELECT [value] AS [Extracted_Time]
FROM [your_table]
CROSS APPLY STRING_SPLIT(CONVERT(varchar, [rowversion_column], 2), '.')
WHERE LEN([value]) = 2
AND CAST([value] AS int) BETWEEN 0 AND 59;Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function converts the rowversion to a varchar data type, using the 2 style to remove the ‘0x’ prefix. The STRING_SPLIT function splits the converted string into substrings based on the ‘.’ separator, and the CROSS APPLY operator applies this function to each row of the table. The WHERE clause filters out substrings that are not valid time components (e.g., milliseconds), ensuring that only the time components are extracted.
Method 18: Using OPENJSON Function
Introduced in SQL Server 2016, the OPENJSON function enables us to parse JSON data and return it as a table. By utilizing this function, we can extract the time from a rowversion.
Here’s an example query:
SELECT JSON_VALUE([value], '$') AS [Extracted_Time]
FROM [your_table]
CROSS APPLY OPENJSON('["' + CONVERT(varchar, [rowversion_column], 2) + '"]')
WHERE ISJSON([value]) = 1
AND LEN([value]) = 2
AND CAST([value] AS int) BETWEEN 0 AND 59;Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function converts the rowversion to a varchar data type, using the 2 style to remove the ‘0x’ prefix. The OPENJSON function parses the converted string as a JSON array with a single element, and the CROSS APPLY operator applies this function to each row of the table. The WHERE clause filters out non-numeric substrings and ensures that only valid time components are extracted.
Method 19: Using REGEXP_REPLACE Function (SQL Server 2017+)
Starting from SQL Server 2017, the REGEXP_REPLACE function is available, allowing us to replace substrings that match a regular expression pattern. By leveraging this function, we can extract the time from a rowversion.
Consider the following query:
SELECT REGEXP_REPLACE(CONVERT(varchar, [rowversion_column], 2), '[^0-9]', '') AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The CONVERT function converts the rowversion to a varchar data type, using the 2 style to remove the ‘0x’ prefix. The REGEXP_REPLACE function removes all non-numeric characters from the converted string, resulting in the extracted time.
Method 20: Using User-Defined Functions
In addition to the built-in functions and methods described above, you can also create your own user-defined functions to extract the time from a rowversion in T-SQL. These functions can encapsulate the necessary logic and be reused across different queries.
Here’s an example of a user-defined function to extract the time from a rowversion:
CREATE FUNCTION dbo.GetTimeFromRowversion(@rowversion rowversion)
RETURNS time
AS
BEGIN
DECLARE @time time;
SET @time = CAST(RIGHT(CONVERT(varchar, @rowversion, 2), 6) AS time);
RETURN @time;
END;To use this function, you can invoke it in a SELECT statement:
SELECT dbo.GetTimeFromRowversion([rowversion_column]) AS [Extracted_Time]
FROM [your_table];Replace [rowversion_column] with the name of your rowversion column and [your_table] with the name of your table. The user-defined function dbo.GetTimeFromRowversion accepts a rowversion parameter and returns the extracted time as a time data type.
