 |
Open source :
production that promote access to the end product's source materials—typically, their source code.
Pasted from <http://en.wikipedia.org/wiki/Open_source>
Primary Key
a unique key can uniquely identify each row in a table, and is closely related to the Superkey concept. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same value (or combination of values) in those columns if NULL values are not used. Depending on its design, a table may have arbitrarily many unique keys but at most one primary key.
Pasted from <http://en.wikipedia.org/wiki/Primary_key>
Candidate Key
a candidate key of a relation is a minimal superkey for that relation; that is, a set of attributes such that
Pasted from <http://en.wikipedia.org/wiki/Primary_Key>
Crow Foot : using to indicate relationship between entities.
--<
OK | One to Many |
NO | Many to One |
NO | Many to Many |
Home Work Exercise Sheet Week2
10/02/2010
Compare
SDLC
Requirements : can do
Sys requirements
User requirements
Client requirements
Specification(Unique) : it is
Prototype Documentation
Client meeting
Supervisor meeting
Journal
Suggest Modeling
Initial Step | Prototype Model |
And then | Chose Waterfall or Prototype Model |
Or | Some degree changeable from Prototype to Waterfall Model |
Prototype Model's Pros
Prototype Model's Cons
Waterfall Model vs Prototype Model
Prototype Strength
Waterfall Strength
Prototype Weakness
Waterfall Weakness
10/02/2010 (wed)
switch
int i=2
switch(i)
{
case 1:
case 2: Console.WriteLine("Hello");
break;
}
If case1 uses without break and no statement sequence, it will work.
for()
for(); = for() {}
*Using ";" after for, it means sentence end.
for(int i=10,j=12; i<0; i++,j--) {}
increment operator
pre increment ++i = i+1
post increment i++ = i+1
Both are same meaning, but increment timing is different.
ex1
int i=5;
int j=i++ +6;
Result 11
ex2
int i=5;
int j=++i +6;
Result 12
ex3
int i=5;
int j=++i - --i + i++;
Console.WriteLine(i);
Console.WriteLIne(j);
Result 6(i)
6(j)
ex4
int i=10;
int j=5;
int k=i-- - --i * --j + j++ / i++;
Console.WriteLine(i);
Console.WriteLine(j);
Console.WriteLine(k);
Result
9(i)
5(j)
-22(k)
k=10-8*4+4/8
=10-32+0
=-22
for : We know how many times it works for loop.
while : We don't know how many times it works for loop.
do while : At least one time.
whille(bool condition)
{
Console.WriteLine(" ");
}
do
{
Console.WriteLine(" ");
} while(bool condition);
string value=Console.Readline();
It means to read someone to input value.
int i=int.Parse(value);
It means to cast from string to integer.
Lotto example
Console.WriteLine("Enter number between 1 and 100");
string number = Console.ReadLine();
int num = int.Parse(number);
while (num != 50)
{
Console.WriteLine("Sorry you missed chance");
Console.WriteLine("Please enter 1 if you want play again otherwise enter 0");
string choice = Console.ReadLine();
int value = int.Parse(choice);
if (value == 0)
{
Console.WriteLine("Good bye");
break;
}
else
{
Console.WriteLine("Enter any number between 1 and 100");
string number1 = Console.ReadLine();
int num1 = int.Parse(number1);
if (num1 == 50)
{
Console.WriteLine("congratulation you won prises of 200,000 dollar");
break;
}
}
}
if (num == 50)
{
Console.WriteLine("congratulation you won prises of 200,000 dollar");
}
Sony VAIO VGNFW53GFW Notebook 
- Cons
- Concluding
The incremental model is good for projects where requirements are known at beginning, but which need functionality early in the project or which can benefit from the feedback of earlier cycyles.
Evolutionary Model (Prototyping)
- Pros
- Cons
- Concluding
