1. Computer Programming and Database Handout

2. Contents Section A: Programming Basics
Section B: Procedural Programming
Section C: Object-Oriented Programming
Section D: Declarative Programming
Section E: Secure Programming
Section F: Database Programming
Computer Programming and Database Handout

3. Section A: Programming Basics
Computer Programming and Software Engineering
Programming Languages and Paradigms
Program Planning
Program Coding
Programming Tools
Program Testing and Documentation
Computer Programming and Database Handout

4. Computer Programming and Software Engineering
The instructions that make up a computer program are often referred to as code.
Programs can have millions of lines of code.
Developed by computer programmers
Computer programming
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5. Computer Programming and Software Engineering
Figure 12-1
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6. Programming Languages and Paradigms
Programming languages are made up of keywords and grammar rules designed for creating computer instructions.
Keywords can be combined with parameters.
Low-level languages typically include commands specific to a particular CPU or microprocessor family.
High-level languages use command words and grammar based on human languages.
The programming paradigm refers to a way of conceptualizing and structuring the tasks a computer performs.
Computer Programming and Database Handout

7. Programming Languages
First generation language
The lowest level programming language; composed of binary digits; typically the only programming language understood by a CPU.
Machine language.
Second generation language
More user friendly than first generation language; uses mnemonics for people to use, such as ADD, SUB, MOV.
Assembly language.
Third generation language
Requires the programmer to specify, step-by-step, exactly how the computer must accomplish a task. Examples: C, Basic, FORTRAN.
Fourth generation language
allows the user to specify the desired result without having to specify step-by-step procedures. Examples: SAS, SPSS, APL.
Fifth-generation language
Based on a declarative programming paradigm.
Lower Higher
First generation language: The lowest level programming language; composed of binary digits;
only programming language understood by CPU.
Second generation language: more user friendly than first generation language; uses mnemonics
for people to use.
Third generation language: requires the programmer to specify, step-by-step, exactly how the
computer must accomplish a task.
Fourth generation language: allows the user to specify the desired result without having to
specify step-by-step procedures.
Visual programming languages: use a graphical environment with mouse; icons and symbols
on the screen, or pull-down menus to make programming easier.

8. Programming Paradigms
The programming paradigm refers to a way of conceptualizing and structuring the tasks a computer performs.
Figure 12-8
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9. Hypertext Markup Language and Extensible Markup Language
An approach to data management in which data are stored in a network of nodes connected by links and are accessed through interactive browsing.
Hyperlinks
The links that connect data nodes in hypertext.
Hypertext document
The combination of nodes, links, and supporting indexes for any particular topic in hypertext.
Hypertext markup language (HTML)
The standard programming language used on the Web to create and recognize hypertext documents.
Extensible markup language (XML)
A programming language designed to improve the functionality of web documents by providing more flexible and adaptable data identification.
Hypertext. An approach to data management in which data are stored in a network of nodes connected by links and are accessed through interactive browsing.
Hyperlinks. The links that connect data nodes in hypertext.
Hypertext document. The combination of nodes, links, and supporting indexes for any particular topic in hypertext.
Hypertext markup language (HTML). The standard programming language used on the Web to create and recognize hypertext documents.
Extensible markup language (XML). A programming language designed to improve the functionality of web documents by providing more flexible and adaptable data identification.

10. Comparison of HTML and XML

11. Program Planning
The problem statement defines certain elements that must be manipulated to achieve a result or goal.
You accept assumptions as true to proceed with program planning.
Known information helps the computer to solve a problem.
Variables vs. constants
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12. Program Planning
Problem statement - Identify the pizza with the lowest price per square inch.
Assuming that there are two pizzas to compare, that both pizzas contain the same toppings, and that the pizzas could be round or square, and given the prices, shapes, and sizes of the two pizzas, the computer will print a message indicating which pizza has the lower price per square inch.
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13. Program Coding
A text editor such as Notepad allows programmers to enter lines of code using a familiar word processing interface.
Figure 12-11
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14. Programming Tools
A Software Development Kit (SDK) is a collection of language-specific programming tools that enables a programmer to develop applications for a specific computer platform.
An Integrated Development Environment (IDE) is a type of SDK that packages a set of development tools into a sleek programming application.
A Component is a prewritten module, typically designed to accomplish a specific task.
An API is a set of application program or operating system functions that programmers can access from within the programs they create.
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15. Program Testing and Documentation
A computer program must be tested to ensure that it works correctly.
Program errors include
Syntax errors
Runtime errors
Logic errors
A Debugger can help a programmer read through lines of code and solve problems.
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16. Program Testing and Documentation
Remarks or “comments” are a form of documentation that programmers insert into the program code.
Figure 12-16
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17. Section B: Procedural Programming
Algorithms
Expressing an Algorithm
Sequence, Selection, and Repetition Controls
Procedural Languages and Applications
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18. Algorithms
Set of steps for carrying out a task that can be written down and implemented.
Start by recording the steps you take to solve the problem manually.
Specify how to manipulate information.
Specify what the algorithm should display as a solution.
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19. Algorithms
Figure 12-21
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20. Expressing an Algorithm
Structured English
Pseudocode
Figure 12-22
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21. Expressing an Algorithm by a Flowchart
The pizza program flowchart illustrates how the computer should proceed through the instructions in the final program.
Figure 12-23
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22. Expressing an Algorithm - Walkthrough
Perform a walkthrough to make sure the algorithm works.
Figure 12-24
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23. Sequence, Selection, and Repetition Controls
Subroutines, Procedures, and Functions
sections of code that are part of the program, but not included in the main sequential execution path.
Figure 12-26
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24. Sequence, Selection, and Repetition Controls
Sequence Control structure
Executing a GOTO command directs the computer to a different part of the program.
Figure 12-25
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25. Sequence, Selection, and Repetition Controls
The computer executes a decision indicated on the flowchart by the question in the diamond shape.
Selection Control structure
Figure 12-27
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26. Sequence, Selection, and Repetition Controls
Repetition Control structure
To execute a loop, the computer repeats one or more commands until some condition indicates that the looping should stop.
Figure 12-28
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27. Procedural Languages and Applications
Popular procedural languages include FORTRAN, COBOL, FORTH, APL, ALGOL, PL/1, Pascal, C, Ada, and BASIC.
The procedural approach is best used for problems that can be solved by following a step-by-step algorithm.
Does not fit well with certain types of problems.
Produces programs that run quickly and efficiently.
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28. Section C: Object-Oriented Programming
Programming language that encapsulates a small amount of data with instructions about what to do with data.
Methods: the instructions about what to do with encapsulated data objects.
Object: the combination of a small amount of data with the data.
Encapsulation: the process of creating an object.
Reusability feature: allows classes created for one purpose to be used in a different object-oriented program if desired.
Object-oriented Program Structure
Object-oriented Languages and Applications
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29. Objects and Classes
An Object represents an abstract or real-world entity.
A Class is a template for a group of objects with similar characteristics.
A Class Attribute defines the characteristics of a set of objects.
Public vs. private attributes
Figure 12-30
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30. Inheritance
Passing certain characteristics from one class to other classes.
Superclass
Subclass
Class hierarchy
Figure 12-33
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31. Methods and Messages
A Method is a segment of code that defines an action.
Collect input, perform calculations, etc.
A method is activated by a message.
Can be defined along with the class they affect.
Polymorphism refers to the ability to redefine a Method in a subclass.
Helps simplify program code.
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32. Object-Oriented Program Structure
Figure 12-39
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33. Object-Oriented Program Structure
Figure 12-40
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34. Object-Oriented Program Structure
When the pizza program runs, on-screen prompts ask for the shape, size, and price of each pizza; then the program displays a message that indicates which pizza is the best deal.
Figure 12-41
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35. Object-Oriented Languages and Applications
SIMULA was believed to be the first object-oriented computer language.
The Dynabook project was the second major development in object-oriented languages.
Popular object-oriented languages today are Ada95, C++, (Visual Basic, and C#).
The OO paradigm results in decreased runtime efficiency, but allows encapsulation, which hides the internal details of objects and their methods.
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36. Section D: Declarative Programming
The Declarative Paradigm
Prolog Facts
Prolog Rules
Input Capabilities
Declarative Languages and Applications
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37. The Declarative Paradigm
Attempts to describe a problem without specifying exactly how to arrive at a solution.
A Fact is a statement for solving a problem.
Rules describe the relationship between Facts.
An approach to the programming process in which the programmer writes a program by specifying a set of statements and rules that define the conditions for solving the problem.
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38. The Declarative Paradigm
A Decision Table is a tabular method for visualizing and specifying rules based on multiple factors.
Figure 12-43
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39. Prolog Facts
Figure 12-44
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40. Prolog Facts
You can query a program’s database by asking a question, called a Goal.
The ?- prompt allows you to query a set of Prolog facts and rules.
Figure 12-46
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41. Prolog Facts
Finding a value for a variable is referred to as Instantiation.
Prolog uses a process called instantiation to
satisfy goals.
Figure 12-47
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42. Prolog Rules
The order of program instructions is critically important.
Figure 12-48
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43. Input Capabilities When the pizza program runs, the pizzainfo rule
Figure 12-51
When the pizza program
runs, the pizzainfo rule
collects input for the prices, the sizes, and the shapes of two pizzas.
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44. Declarative Languages and Applications
Declarative programming languages are most suitable for problems that pertain to words and concepts rather than to numbers.
Highly effective programming environment.
Not commonly used for production applications.
Minimal input and output capabilities.
Poor performance on today’s personal computer architecture.
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45. Section E: Event Driven Programming
A Visual Development Environment (VDE) provides programmers with tools to build substantial sections of a program.
Form design grid
Control
Properties
Event
Event- handling code
Figure 12-12
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46. Program Coding (Event Driven)
Controls, such as the
Best Deal button, can be selected by a programmer from a properties list.
Here a programmer is selecting the background color for the Best Deal button.
Figure 12-13
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47. Program Coding (Event Driven)
Figure 12-14
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48. Section F: Secure Programming
Black Hat Exploits
Secure Software Development
Mitigation
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49. Black Hat Exploits
Today’s operating systems, utilities, and application software are full of defects that create security holes, which are exploited by black hats.
A buffer overflow (also called a buffer overrun) is a condition in which data in memory exceeds its expected boundaries and flows into memory areas intended for use by other data.
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50. Black Hat Exploits Figure 12-53
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51. Black Hat Exploits
Verbose error messages can also present attackers with information about the directory location of programs or files, the structure of a database, or the layout of the program in memory.
Figure 12-54
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52. Secure Software Development
Most software security problems can be traced back to defects that programmers unintentionally introduce in software during design and development.
Formal methods help programmers apply rigorous logical and mathematical models to software design, coding, testing, and verification.
Threat modeling (risk analysis).
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53. Secure Software Development
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54. Secure Software Development
An attack tree is a hierarchical diagram of potential attacks against a system
Figure 12-56
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55. Secure Software Development
Defensive programming (also referred to as secure programming) is an approach to software development in which programmers anticipate what might go wrong as their programs run and take steps to smoothly handle those situations.
Source code walkthroughs
Simplification
Filtering input
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56. Secure Software Development
Signed code is a software program that identifies its source and carries a digital certificate attesting to its authenticity.
Figure 12-57
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57. Mitigation
Despite defensive programming and other tactics to produce secure software, some defects inevitably remain undiscovered in products that end up in the consumers’ hands.
When bugs are discovered, the programmer’s remaining line of defense is to produce a bug fix, or patch.
Figure 12-58
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58. Mitigation
Take the following steps to avoid security problems that stem from software defects.
Select applications from software publishers with a good security track record.
Watch for patches and apply them.
Consider using open source software, which has been extensively reviewed by the programming community.
Keep your firewall and antivirus software deployed and up-to-date.
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59. Section G: Structured Query Language (SQL)
SQL is the language for querying and updating databases.
“universal” database language
Developed in the mid-1970’s by IBM
Original name SEQUEL changed to SQL in 1980.

60. Plan Ahead for a Query Select the fields for the query
Determine which table or tables contain these fields
Determine criteria
Determine sort order
Determine grouping
Determine any update operations to be performed

61. Creating a New SQL Query in Access2007
Hide the Navigation Pane
Click Create on the Ribbon to display the Create tab
Click the Query Design button on the Create tab to create a query
Close the Show Table dialog box without adding any tables
Click the View button arrow to display the View menu
Click SQL View to view the query in SQL view