self-reference

In a worksheet function in Excel, how do you self-reference the cell, column or row you're in? Note that this is extremely useful for conditional formatting. Matt J where F13 is the cell you need to reference: =CELL("Row",F13) yields 13; its row number =CELL("Col",F13) yields 6; its column number; =SUBSTITUTE(ADDRESS(1,COLUMN(F13)*1,4),"1","") yields F; its column letter For a cell to self-reference itself: INDIRECT(ADDRESS(ROW(), COLUMN())) For a cell to self-reference its column: INDIRECT(ADDRESS(1,COLUMN()) & ":" & ADDRESS(65536, COLUMN())) For a cell to self-reference its row: INDIRECT

How to enforce a constraint of foreign key on columns of same table in SQL while entering values in the following table: employee : empid number, manager number (must be an existing employee) instanceOfObject CREATE TABLE TABLE_NAME ( `empid_number` int ( 11) NOT NULL auto_increment, `employee` varchar ( 100) NOT NULL , `manager_number` int ( 11) NOT NULL , PRIMARY KEY (`empid_number`), CONSTRAINT `manager_references_employee` FOREIGN KEY (`manager_number`) REFERENCES (`empid_number`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 Hope it helps! Oracle call this a self-referential integrity constraint.

I have the following scenario in my database. It is a record of Studies and those studies have other studies as prerequisites. In my DB design, it looks like this: And my code looks something like this: public class Study { public int ID { get; set; } public string Topic { get; set; } public byte TypeID { get; set; } public virtual StudyType Type { get; set; } public bool Deprecated { get; set; } public virtual ICollection<Study> Prerequisites { get; set; } } public class StudyType { public byte ID { get; set; } public string Name { get; set; } public virtual ICollection<Study> Studies { get;

I read quite a number of posts of programmers that run into the Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values -exception when using a self-referencing relationship in Entity Framework. I am trying to get a parent-child relationship to work: public class Category { public int CategoryId { get; set; } public string Name { get; set; } public int ParentId { get; set; } public Category Parent { get; set; } public List<Category> Children { get; set; } } This is the configuration I

I have a User that can have collection of users he likes... Another user can have collection of users he likes.... If User A likes User B and if User B likes User A, then they get to hang out. I need to send each other their contact info. How do we represent such a model in Entity Framework Code First? public class User { public int UserId { get; set; } public int? UserLikeId { get; set; } public virtual UserLike UserLike { get; set; } } public class UserLike { public int UserLikeId { get; set; } public int UserId { get; set; } public virtual User User { get; set; } public virtual ICollection

I know it is possible to create a self referencing list in languages like Python: >>> my_list = [1,2] >>> my_list.append(my_list) >>> print my_list [1,2,[...]] >>> print my_list[0] 1 >>> print my_list[2] [1,2,[...]] What algorithms benefit from self referencing lists? I cannot think of one. Thanks. Self-referencing lists, and, generally speaking, circular data structures, can be caused when representing a graph using data structures. For example, consider this naive representation of a graph: Each node is either an atomic value, or a list of nodes that it is linked to. A circle may cause a

How can I get a reference to a module from within that module? Also, how can I get a reference to the package containing that module? import sys current_module = sys.modules[__name__] If you have a class in that module, then the __module__ property of the class is the module name of the class. Thus you can access the module via sys.modules[klass.__module__] . This is also works for functions. You can get the name of the current module using __name__ The module reference can be found in the sys.modules dictionary. See the Python documentation One more technique, which doesn't import the sys

I have created an entity type that has multiple collection properties that reference items of the same type. In other words, it reflects a single database table in which the rows are arbitrarily grouped, such that a row may appear in multiple groups. In the following simplified example, the Person class has Brothers and Sisters collection properties that also reference Person entities: public class Person { public Person() { Brothers = new Collection<Person>(); Sisters = new Collection<Person>(); } [Key] public string Name { get; set; } public int Age { get; set; } public virtual ICollection

With Polymorphic this in TypeScript 1.7, as I discovered here , we can define a method in a class with a return type of this , and automatically, any classes that extend that class and inherit the methods, will have their return types set to their respective this type. Like so: class Model { save():this { // return type: Model // save the current instance and return it } } class SomeModel extends Model { // inherits the save() method - return type: SomeModel } However, what I'm after is to have an inherited static method with a return type referencing the class itself. It's best described in