Answer:
a) We know that atleast one or more author writes a book.
Symbol to indicate one or more is (B)
So the correct option is B
b) We know that zero to multiple books are written by any author.
Symbol to indicate zero or more is (A)
So the correct option is A
c) The fourth option is correct if we replace by many to many relationship and generate a new entity.
So the relationship betweem author and contract is one to many. So we know that there is atleast one author that represent in symbol d and books has atleast 0 that represent in symbol c.
So Fourth Option is correct d at blue side and c at red side.
d) There are two forirgn keys in table Contract one is from AuthorId and other is ISBN.
So correcct option is C
Answer:
Singleton pattern is the pattern for design that is build using the global variables which creates a lot of drawback in the designing. Singleton pattern are considered with the global variable and thus cannot be bound into single unit which complexes the components in design.
They have a loose coupled variables in design and also does not show the property of the multi-threading .These feature are responsible for the decrement in the performance and thus are not highly preferred choice for the pattern.So, it is known as the "anti- pattern".
We use Boolean Logic operators because it saves more time when searching a topic. This connects pieces of information in a search allowing you to find exactly what you are looking for.
The answer is perspective, because you need a point of view (perspective) in order to make a design, a great design/
Answer:
Routers
Explanation:
Essentially a router is a device used in networking that route packets of data from one computer network to another.