While you have a few years of experience for one of the language ( VB or C#), you might found some time is needed for yourself when you want to code another language. It is easy to read and understand them but when it comes to write, you might become not as fast as when you code using the other language. This is because of the syntax! (It makes me felt that this is just like some people can understand Cantonese but cannot speak in Cantonese. hehe..)
First, C# is case sensitive while VB is case insensitive.
So,
you can do this to C# ==> Var i = 1; Var I = 10;
But,
you cannot do this to VB ==> Dim i as Integer = 1 Dim I as Integer = 10
the compiler will definitely complain about double declaration.
Sunday, January 25, 2015
Thursday, January 22, 2015
Consideration before adopting SCRUM
This article explain well on the key points you should clarified, be sure that you don't have those thinking before jump into SCRUM.
https://www.scrumalliance.org/community/articles/2015/january/consideration-before-adopt-scrum.aspx
https://www.scrumalliance.org/community/articles/2015/january/consideration-before-adopt-scrum.aspx
Monday, January 12, 2015
5 types of system database in SQL
5 types of system database in SQL:
1) Master database
2) Resource database
3) Tempdb database
4) Model database
5) msdb database
1) Master database
- The ''VID''(very important database) of the SQL. Without this database, the server cannot be started. (because it store the initializing information)
- Act as a identity card for the server, because it store all the system level information.
(store all the authorized user information, logon accounts, system configuration settings and others metadata)
- The system object used to store in this master database but it is now in the resource database.
- Physical file : master.ldf and master.mdf
- It is not advise to : change any logon information or change information in the master database. In fact, a lot of changing, dropping, renaming, creating action is not allowed in this database. ( as per mention in msdn.
- If you have to do something with the master database, such as create user object , you are advice to backup the master database. In case of the master database unusable, you can restore the master database or rebuild the master (this is for severe damage, server not able to restart , and this will cause all the system database being rebuild ) .
1) Master database
2) Resource database
3) Tempdb database
4) Model database
5) msdb database
1) Master database
- The ''VID''(very important database) of the SQL. Without this database, the server cannot be started. (because it store the initializing information)
- Act as a identity card for the server, because it store all the system level information.
(store all the authorized user information, logon accounts, system configuration settings and others metadata)
- The system object used to store in this master database but it is now in the resource database.
- Physical file : master.ldf and master.mdf
- It is not advise to : change any logon information or change information in the master database. In fact, a lot of changing, dropping, renaming, creating action is not allowed in this database. ( as per mention in msdn.
- If you have to do something with the master database, such as create user object , you are advice to backup the master database. In case of the master database unusable, you can restore the master database or rebuild the master (this is for severe damage, server not able to restart , and this will cause all the system database being rebuild ) .
Wednesday, January 7, 2015
Object Oriented programming
Module is a collection of classes,
Class is a definition,
and Object is a collection of data.
The object is actually an instance of class, it is 'born' based on the definition of the class. While module is a collection of classes.
This is for biology lover:
We have Kingdom, Family , Genus .....( I forgotten what I had memorized during high school)..
what makes those Families under that Kingdom is due to they have some similarities, but each of them is different.
For example, human and chimpanzee are under Hominidae, both is warm blood , about similar structure. In programming, human and chimpanzee inherit the definition in the Hominidae. Let's imagine them as each individual class. Human can walk, Chimpanzee can walk, Human extend from the base class and have something they have but Chimpanzee doesn't has.
in code: class Human(Hominidae)
Human us a derive class and Hominidae is a base class.
In the human class, we have each individual human , just like U and I. We are an object , that is an instance of the human. We represent the human. ( object is a collection of data based on class)
Now, move a level up, before Hominidae, we have a super family which can act as module. Module is a collection of classes.
I had the idea after this interesting video that describe OOP with the city planner example. Here is the link.: https://www.youtube.com/watch?v=P1WcKEgvRFE
Usually, this concept is widely practice when a programmer do programming, but one mey notknow how to explain it. I normally will have a class contain all related functions. It is more manageable and cleaner in this way. For each function, try to let it only have a "mission" to archive.
Programming is an art. :)
Class is a definition,
and Object is a collection of data.
The object is actually an instance of class, it is 'born' based on the definition of the class. While module is a collection of classes.
This is for biology lover:
We have Kingdom, Family , Genus .....( I forgotten what I had memorized during high school)..
what makes those Families under that Kingdom is due to they have some similarities, but each of them is different.
For example, human and chimpanzee are under Hominidae, both is warm blood , about similar structure. In programming, human and chimpanzee inherit the definition in the Hominidae. Let's imagine them as each individual class. Human can walk, Chimpanzee can walk, Human extend from the base class and have something they have but Chimpanzee doesn't has.
in code: class Human(Hominidae)
Human us a derive class and Hominidae is a base class.
In the human class, we have each individual human , just like U and I. We are an object , that is an instance of the human. We represent the human. ( object is a collection of data based on class)
Now, move a level up, before Hominidae, we have a super family which can act as module. Module is a collection of classes.
I had the idea after this interesting video that describe OOP with the city planner example. Here is the link.: https://www.youtube.com/watch?v=P1WcKEgvRFE
Usually, this concept is widely practice when a programmer do programming, but one mey notknow how to explain it. I normally will have a class contain all related functions. It is more manageable and cleaner in this way. For each function, try to let it only have a "mission" to archive.
Programming is an art. :)
Thursday, January 1, 2015
3 DES - Security / encryption
3DES
- Triple data encryption Algorithm
-Encrypts data 3 times using 64-bit keys
-symmetric-key block cipher
-widely use on electronic payment.
- Triple data encryption Algorithm
-Encrypts data 3 times using 64-bit keys
-symmetric-key block cipher
-widely use on electronic payment.
RSA - Security / encryption
RSA is public key encryption that used for data sending over internet.
- It is well known industry strength encryption, this 'recognition' is given based on the fact that there is no easy way to factor very large number. To factor a very large amount of computer processing time and power is needed.
- Uses asymmetric cryptography algorithm i.e. it uses two different key to achieve encryption.
- Also know as public key cryptography because the give is given to everyone, to the public. The private key is kept privately, private key is a prime factor. With the public key, everyone / anyone can encrypt the message and reply. Only the person that know the private key can use the factor to decode the message.
- For example(just as an example) : public key = A, message = B,
user will send the result of A * B to me and I will use C mode A to get message as B .
- It is well known industry strength encryption, this 'recognition' is given based on the fact that there is no easy way to factor very large number. To factor a very large amount of computer processing time and power is needed.
- Uses asymmetric cryptography algorithm i.e. it uses two different key to achieve encryption.
- Also know as public key cryptography because the give is given to everyone, to the public. The private key is kept privately, private key is a prime factor. With the public key, everyone / anyone can encrypt the message and reply. Only the person that know the private key can use the factor to decode the message.
- For example(just as an example) : public key = A, message = B,
user will send the result of A * B to me and I will use C mode A to get message as B .