In SQL, the LAST_VALUE function is used to retrieve the last value in a set of values. This can be especially useful when working with table types in SQL, where you may need to extract the last value from a specific column.

Here is an example of how the LAST_VALUE function can be used with a table type:

-- Create a table type
CREATE TYPE EmployeeTable AS TABLE
(
    EmployeeID INT,
    EmployeeName VARCHAR(50),
    JoiningDate DATE
);

-- Declare a variable of the table type
DECLARE @Employees EmployeeTable;

-- Insert sample data into the table variable
INSERT INTO @Employees (EmployeeID, EmployeeName, JoiningDate)
VALUES
    (1, 'John Doe', '2021-01-01'),
    (2, 'Jane Smith', '2021-02-15'),
    (3, 'Mike Johnson', '2021-03-10');

-- Retrieve the last joining date using LAST_VALUE
SELECT DISTINCT
    EmployeeID,
    EmployeeName,
    LAST_VALUE(JoiningDate) OVER (ORDER BY EmployeeID) AS LastJoiningDate
FROM
    @Employees;

In the above example, we first create a table type called EmployeeTable with three columns: EmployeeID, EmployeeName, and JoiningDate. We then declare a variable @Employees of this table type and insert some sample data into it.

Next, we use the LAST_VALUE function with the OVER clause to retrieve the last joining date for each employee. The LAST_VALUE function is applied on the JoiningDate column and is ordered by the EmployeeID. The result is returned with distinct EmployeeID, EmployeeName, and the last joining date.

By using the LAST_VALUE function in conjunction with table types, we can easily extract the last value from a specific column within the table type. This can be helpful in various scenarios, such as finding the most recent date or the latest record inserted in a table type.

#SQL #TableType