嵌套SQL Server事务执行级联删除

Suppose I have a table called Companies that has a DepartmentID column. There's also a Departaments table that has as EmployeeID column. Of course I have an Employee table as well. The problem is that I want to delete a company, so first i have to delete all the employees for every departament and then all the departaments in the company. Cascade Delete is not an option, therefore i wish to use nested transactions. I'm new to SQL so I would appreciate your help.Suppose I have a table called Companies that ha