Что такое рекурсивная хранимая процедура?sql-73

CREATE PROCEDURE RecursiveFactorial @n INT, @result INT OUTPUT
AS
BEGIN
    -- Базовый случай
    IF @n <= 1
        SET @result = 1
    ELSE
    BEGIN
        -- Рекурсивный вызов
        DECLARE @temp INT
        EXEC RecursiveFactorial @n - 1, @temp OUTPUT
        SET @result = @n * @temp
    END
END;

CREATE PROCEDURE GetEmployeeHierarchy @managerId INT, @level INT = 0
AS
BEGIN
    -- Вывод текущего уровня
    SELECT e.id, e.name, @level as level
    FROM employees e
    WHERE e.manager_id = @managerId;

    -- Рекурсивный вызов для подчиненных
    DECLARE @subordinateId INT
    DECLARE subordinate_cursor CURSOR FOR
        SELECT id FROM employees WHERE manager_id = @managerId;

    OPEN subordinate_cursor
    FETCH NEXT FROM subordinate_cursor INTO @subordinateId

    WHILE @@FETCH_STATUS = 0
    BEGIN
        EXEC GetEmployeeHierarchy @subordinateId, @level + 1
        FETCH NEXT FROM subordinate_cursor INTO @subordinateId
    END

    CLOSE subordinate_cursor
    DEALLOCATE subordinate_cursor
END;

CREATE PROCEDURE FindPath @startNode INT, @endNode INT, @path VARCHAR(MAX) = ''
AS
BEGIN
    SET @path = @path + CAST(@startNode AS VARCHAR) + '->'

    IF @startNode = @endNode
        PRINT @path
    ELSE
    BEGIN
        DECLARE @nextNode INT
        DECLARE edge_cursor CURSOR FOR
            SELECT to_node FROM graph_edges WHERE from_node = @startNode;

        OPEN edge_cursor
        FETCH NEXT FROM edge_cursor INTO @nextNode

        WHILE @@FETCH_STATUS = 0
        BEGIN
            IF CHARINDEX(CAST(@nextNode AS VARCHAR), @path) = 0
                EXEC FindPath @nextNode, @endNode, @path
            FETCH NEXT FROM edge_cursor INTO @nextNode
        END

        CLOSE edge_cursor
        DEALLOCATE edge_cursor
    END
END;

WITH EmployeeCTE AS (
    -- Базовый случай
    SELECT id, name, manager_id, 0 AS level
    FROM employees
    WHERE manager_id IS NULL

    UNION ALL

    -- Рекурсивная часть
    SELECT e.id, e.name, e.manager_id, cte.level + 1
    FROM employees e
    JOIN EmployeeCTE cte ON e.manager_id = cte.id
)
SELECT * FROM EmployeeCTE;

CREATE PROCEDURE IterativeFactorial @n INT, @result INT OUTPUT
AS
BEGIN
    SET @result = 1
    WHILE @n > 1
    BEGIN
        SET @result = @result * @n
        SET @n = @n - 1
    END
END;