The Importance Of Databases Computer Science Essay

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Nowadays, database are integrated in our daily life, maybe you don realize but almost everything are related to database. For an example: purchase stuff from the supermarket or even using an internet. In earlier day, they are record without using computer, but with crude accounting systems that banks used to use over 500 years ago. In 90s database become more accurate and easily maintain, and currently, the focus is on completely automating most of the database management administration.

Database is share logically related data to a network of pc, database is design to meet the needs of an organization. Database is a single, and also a large place to store all the data together, and can be used by many department and users. To manage the database we will need a system known as Database management system (DBMS). The DBMS is the software that interacts with the users, by allow users to create, maintain, control and define access to the database

Define of Question 1

1.0 What is Database and why it's so important?

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Database plays an important role in manage information, database ia a shared corporate resource. Database is not just holds the basic information of an organization but also description of this data, the description of this data is known as system catalog, or metadata, Database are separates with the structure, even the internal information has been modifies, the existing information are unaffected, remain the same mean they don directly depend upon what has been modified.

The DBMS is the software that interacts with the users, by allow users to create, maintain, control and define access to the database.Database consist of a table which contain few important element, without this few element database structure would not be complete, those element are relation, attribute, domain, tuple, degree and cardinality.

Relation predefined row or column format, for storing information in a relational database and some disorder set of tuples which share the same type of data. Relations are equivalent to tables, Figure 1.1show which part is relation.

Attribute is single data item that related to a database object. The database schema associates with one or more attribute with each database entity, they also known as named column of a relation., Figure 1.2 show how attribute look like.

The Domain Name powerful feature of the relational model, it is a hierarchical, distributed database, domain name is more detail, description compare to attribute, its elaborate of attribute. It is described in a number of publications and articles: A domain name is a series of labels. For an example: DOB is a attribute, in domain name DOB is Date Of Birth and its validation the entry, the entry must be possible value of staff birthday dates if entry is not valid entry, entry will not be accept. The format validation of entry is in domain definition, the validation is follow the information given in domain definition, Figure 1.3 show how Domain look like.

1.4 Tuple

Tuple

Tuple (figure 1.4)

Tuple is a term from set theory which refers to a collection of one or more attributes, it is a relation that in row format, In a relation each row will contain few values, one of each attribute, relation will still be the same relation, but tuple able to appear in any order. Actually its carry the same meaning, Figure 1.4 show structure of Tuple.

Student Table (Figure 2.1) is one of the Table in student information system, in relational design it every database come with a primary key, primary key is a combination of columns that specify a row in a different way. The primary key of Student Table is StudentNo, because all of the attribute may have chances to be same with other information but StudentNo is unique, no student will get same StudentNo that why it will be chosen to be primary key.

CentreNo Table (Figure 2.2) is one of the Table in student information system, In CentreNo table, primary key is CentreNo,. In student Table, CentreNo was a foreign key, foreign key is an attribute that close up a relationship by identifying the main entity. In centreNo table, StudentNo become foreign key. It's a relationship between student table and centre table are to get the information of student study at which centre.

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Staff Table (Figure 2.3) is one of the Table in student information system, In Staff Table, StaffNo is the primary key, and the foreign key is centreNo. In Centre Table, CentreNo was the Primary key but in Staff Table it about staff and which centre is the staff working at so there is an relationship between staff and centre

CourseNo Table (figure 2.4) is one of the Tables in student information system, In Course Table, the primary key is CourseNo and the foreign key is the StudentNo. The relationship between courseNo and studentNo is list out specific student study at which centre, so that the staff at the centre can easily to get the specific student information.

This is the relationship between tables, the attribute of Centre Table (CentreNo) connect to attritube of Course Table (CentreNo), so that these two tables will become related, Centre Table will able to see the information of Course Table, and attribute of Course Table (StaffNo) is connect to the attribute of Staff Table (StaffNo), so that these two tables will become related, Course Table will able to see the information Staff Table. Lastly attribute Staff Table of (StaffNo) are connect to attribute (StudentNo) of Student Table, two table will become related and Staff Table will able to see the information of Student Table.

The entity-relationship model is a way of graphically display the logical relationships of object to create a database. The entity-relationship data model views the real world as a set of basic objects (entities) and relationships among these objects. It is intended primarily for the database design process by allowing the specification of an enterprise scheme. This represents the overall logical structure of the database. The ER model was created by Peter Pin-Shan Chen on 1970, he study at Massachusetts Institute of Technology (MIT).

Creation of an entity relationship diagram this is one of the step to design database, helps the designers to comprehend and to specify the desired components of the database and the relationships between those components. An entity relationship model is a diagram that containing entities, and relationships between them, and attributes of the entities and the relationships.

Answer Of Question 2

1.1 What is Microsoft Access?

Microsoft Access is a Relational Database Management System (RDBMS), Microsoft Access can run and do the work very well even in a single computer, it's for small business to organize and manage data, then accessed remotely from multiple client machines and Microsoft access is bundled as part of the Microsoft Office suite, easy to be install and its user friendly.

Microsoft Access (Figure 1.1)

Figure 1.1 show how Microsoft Access look like, its clean and user friendly GUI (Graphical User Interface), all function are in button form. There are many section in Access, first will look thru to table section.

Figure 1.2 it's is All Tables label in Access. All Tables label allow user to see how many table in a database. When you have create the table, the name of the table will appear at the tables label, as you can see in figure 1.2 there are 4 table at it, which is CentreNo, StaffNo, CourseNo, and StudentNo.

1.3 View Option

View Option (Figure 1.3)

Microsoft Access come with the 4 view option, view option include: form view, datasheet view, layout view, design view. In Form view, display information in a way that other respond more easily. In datasheet view, able to let user enter information more faster, design view allow user to modify and create form that for other to use. Tthe last one is layout view, will make the information more into report form.

1.4 Layout View

Layout View (Figure 1.4)

Layout View is a WYSIWYG (What You See Is What You Get), a view that let user changes to other table or form immediately to see the effect that you just changes. If user desired, it also can change to layout view, by choose the view control anc choosing the layout view, table will become selectable.

2.0 Create a Database

Getting Started Window (Figure 2.0)

After you open Microsoft Access, you should see the getting started window, next press the blank database to begin the process. As shown in figure 2.0.

2.1 Name The Database

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Figure 2.1

After you press "Blank Database", at the right pane of the Getting Started window will change to a column that let you rename the name of the database, like figure 2.1. Type the name that you want inside the text box, and press the Create button to begin building your data.

2.2 Create a table

Figure 2.2

This is how Microsoft Access look like, now is in spreadsheet-style interface, You can click anywhere in the row that has (New) as its ID to start enter data.

Figure 2.3

Next you can start what information that you want, and other contact information in the fields provided. As soon as you begin typing, Access creates an ID number and then adds another new row with "New" as its ID.

2.4 First table Of Student Information

StudentNo Table (Figure 2.4)

Figure 2.4 show the first table of student information, which is studentNo Table. The primary key of Student Table is StudentNo, because all of the attribute may have chances to be same with other information but StudentNo is unique, no student will get same StudentNo that why it will be chosen to be primary key. As you can see StudentNo, fName, Lname, Sex, DOB, and CentreNo are attribute.

2.5 Second Table Of Student Information

CentreNo Table (Figure 2.5)

CentreNo Table (Figure 2.5) is one of the Table in student information system, In CentreNo table, primary key is CentreNo,. In student Table, CentreNo was a foreign key, but in centreNo table, StudentNo become foreign key. It's a relationship between student table and centre table are to get the information of student study at which centre.

2.6 Third Table Of student Information

StaffNo Table (Figure 2.6)

StaffNo Table (Figure 2.6) is one of the Table in student information system, In Staff Table, StaffNo is the primary key, and the foreign key is centreNo. In Centre Table, CentreNo was the Primary key but in Staff Table it about staff and which centre is the staff working at so there is an relationship between staff and centre Table, In StaffNo Table also include other attribute such as course, fName (First name), lName (Last name), DOB (Date Of Birth) ,and studentNo.

2.7 Fourth Table of Student Information

CourseNo Table (Figure 2.7)

CourseNo Table (figure 2.7) is one of the Tables in student information system, In Course Table, the primary key is CourseNo and the foreign key is the StudentNo. The relationship between courseNo and studentNo is list out specific student study at which centre, so that the staff at the centre can easily to get the specific student information. In CourseNo table, also include other attribute such as : fName ,lName, Sex, CentreNo, StaffNo, and StudentNo.

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All Table Label (Figure 2.8)

After you finished enter all the information into the four tables, your Table Label should be look like Figure 2.8.

2.9 Creating a Primary Key

Figure 2.9

To creating a Primary Key first select the table you like to work with, next click the design view.

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Figure 3.0

Next you will see the screen like Figure 3.0, you will notice there has a small key icon beside the ID column, that the primary key.

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Figure 3.1

To change the primary key into StudentNo, first right click the StudentNo column then select the primary key button like Figure 3.1. If everything goes fine, you will see the primary key icon beside the StudentNo column. Like figure 3.2

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Figure 3.2

The step are repeated, and now all the table should belong with they own primary key instead of ID.

Figure 3.3

Figure 3.3 show Centre Table has done assign the primary key into centreNo, the key icon show that centreNo is the primary key.

Figure 3.4

Same to Staff Table, Figure 3.4 show Staff Table has done assign the primary key into StaffNo, the key icon show that StaffNo is the primary key.

Figure 3.5

On the last table do the same thing, Figure 3.5 show course Table has done assign the primary key into CourseNo, the key icon show that CourseNo is the primary key.

3.6 Create a Relationship

Figure 3.7

Next, open the Relationships Tool. First you will see the Database Tools tab and select it on the bar. Next click the Relationships button, like Figure 3.7

Figure 3.8

If this is the first relationship you've created in the current database, the Show Tables dialog box will appear, like Figure 3.8. Now choose the table that you like to include in the

relationship and click the Add button.

Figure 3.9

You'll now see the relationship diagram that without a link or connection, like Figure 3.9.As you can see creating a relationship between the four tables which is StudentNo, CentreNo, StaffNo, and CourseNo. At the previous step we added the entire four table to the diagram, and there are no link between them so this mean that still don have apply any relationships between those tables.

Figure 4.0

To create a relationship click on the primary key and drag it to the foreign key. You will see the Edit Relationships dialog, like Figure 4.0 makes sure that each run in our database takes place along an established route. Therefore, the table's primary key (ID) is the primary key of the relationship and the Route attribute in the Runs table is the foreign key. Look at the Edit Relationships dialog and verify that the correct attributes appear.

Also in this step, you will need to decide whether you want to enforce referential integrity. If you select this option, Microsoft Access will make sure that all records in the Runs table have a right record in the table at all times. As you can see, its selected referential integrity enforcement. Once it's finished, click the Create button to close the Edit Relationships dialog.

Figure 4.1

After clicks create, something like Figure 4.1 should be appearing. Repeat this process until the relationship complete. Like Figure 4.2.

Figure 4.2

The relationship has been complete. Now back to the Tables you will realize beside the column there has a "+" sign. Like Figure 4.3.

Figure 4.3

The "+" sign button, is to see the information that related to the column. Click the "+" sign button to expand it. After expand it will look Figure 4.4.

Figure 4.4

After expand the StudentNo Tables, if everything goes fine, it will show the information that related to StaffNo, CourseNo, and State tables, other tables will also have the same thing appear. Now the database has finished and ready to be use.

Conclusion & Recommendation

Databases are crucial for organizing client information, generating reports, and keeping track of financial records. Many times, you can find affordable software to suit your needs, but sometimes a custom solution may be more appropriate. We won't able to manage the information properly if database doesn't exist.

In Future perhaps databases should be smart enough by themselves to send a customer an email message if a payment is due on a certain date and it is not received, or even able to control data redundancy themselves, and database would be able to update their database automatically by themselves.

Database really bring a lot of benefit to us, I can't find any disadvantage of using them. But hopefully in the future security of database will be improve, because now security of database still got a lot of thing that need to improve, hope the security will be improve soon so that our privacy or information will be protected. Potential of Database still haven been fully bring out, but I sure someday database will be more easier, less complex to be use.