constraints

What is the purpose of naming your constraints (unique, primary key, foreign key)? Say I have a table which is using natural keys as a primary key: CREATE TABLE Order ( LoginName VARCHAR(50) NOT NULL, ProductName VARCHAR(50) NOT NULL, NumberOrdered INT NOT NULL, OrderDateTime DATETIME NOT NULL, PRIMARY KEY(LoginName, OrderDateTime) ); What benefits (if any) does naming my PK bring? Eg. Replace: PRIMARY KEY(LoginName, OrderDateTime) With: CONSTRAINT Order_PK PRIMARY KEY(LoginName, OrderDateTime) Sorry if my data model is not the best, I'm new to this! Here's some pretty basic reasons. (1) If a

In PostgreSQL 8 is it possible to add ON DELETE CASCADES to the both foreign keys in the following table without dropping the latter? # \d scores Table "public.scores" Column | Type | Modifiers ---------+-----------------------+----------- id | character varying(32) | gid | integer | money | integer | not null quit | boolean | last_ip | inet | Foreign-key constraints: "scores_gid_fkey" FOREIGN KEY (gid) REFERENCES games(gid) "scores_id_fkey" FOREIGN KEY (id) REFERENCES users(id) Both referenced tables are below - here: # \d games Table "public.games" Column | Type | Modifiers ----------+------

Is there a way to get the following function declaration? public bool Foo<T>() where T : interface; ie. where T is an interface type (similar to where T : class , and struct ). Currently I've settled for: public bool Foo<T>() where T : IBase; Where IBase is defined as an empty interface that is inherited by all my custom interfaces... Not ideal, but it should work... Why can't you define that a generic type must be an interface? For what it's worth, I want this because Foo is doing reflection where it needs an interface type... I could pass it in as a normal parameter and do the necessary

I have a table whose primary key is used in several other tables and has several foreign keys to other tables. CREATE TABLE location ( locationID INT NOT NULL AUTO_INCREMENT PRIMARY KEY ... ) ENGINE = InnoDB; CREATE TABLE assignment ( assignmentID INT NOT NULL AUTO_INCREMENT PRIMARY KEY, locationID INT NOT NULL, FOREIGN KEY locationIDX (locationID) REFERENCES location (locationID) ... ) ENGINE = InnoDB; CREATE TABLE assignmentStuff ( ... assignmentID INT NOT NULL, FOREIGN KEY assignmentIDX (assignmentID) REFERENCES assignment (assignmentID) ) ENGINE = InnoDB; The problem is that when I'm

I'm trying to place a UIImageView at the top of a UIScrollView and when I constrain the UIScrollView to the sides of the View Controller and constrain the UIImageView to the top and make the width of the UIImageView equal to the UIScrollView it makes the UIImageView way wider than the UIScrollView, and much taller than expected. Any idea what I'm doing wrong? Storyboard: Preview: Check that following constraints are added to your view: Go to Storyboard -> Select your view Now at right-bottom corner you can see small buttons to add constraints Select "Pin" button And mark all 4 constraints for

Possible Duplicate: C# generic constraint for only integers Greets! I'm attempting to set up a Cartesian coordinate system in C#, but I don't want to restrict myself to any one numerical type for my coordinate values. Sometimes they could be integers, and other times they could be rational numbers, depending on context. This screams "generic class" to me, but I'm stumped as to how to constrict the type to both integrals and floating points. I can't seem to find a class that covers any concept of real numbers... public class Point<T> where T : [SomeClassThatIncludesBothIntsandFloats?] { T myX,