Database Applications - Research Paper Example

Today, most applications are already database driven, web pages for instance. The video ials talk about what a database is and its advantages over flat files, what is a Relational Database Management System (RDBMS) and the major database objects used in it, and how to create relational database tables. Now, what is a database? It is one or more files optimized to work together for a very structured storage, efficient and quick retrieval of data, ensuring data accuracy and integrity. It can simply be files or may require server software in managing connections and regulating access to the files.

It mainly focuses on the safe management and maintenance of data, and providing access to multiple applications and users simultaneously. Despite its complexity as compared to flat text files and spreadsheets, it actually makes things easier considering the weaknesses of the latter (i.e. redundant information, outdated data, file size, complex protection of data from unauthorized use and from becoming corrupt), particularly when working with large-scale applications. These issues aforementioned are taken cared of Relational Database Management System (RDBMS), such that the flexibility and security of data outweighs the complexity of the system.

Codd's idea was to break down a long row of data fields into smaller tables describing specific subsets of the data collected, ultimately reducing the data footprint and cost. Furthermore, it enforces data integrity by ensuring data type correctness (by using strong data types), eliminating redundant data (by saving data entities in just one place), disallowing harmful deletes (by using key constraints), and guarantees efficient retrieval and manipulation of data (by splitting up data into chunks).

With SQL Server 2005 Express Edition, you get the advantages of RDBMS. RDBMS also offers additional services such as multi-user access, controlling access, security (authentication and authorization to perform tasks), administrative tasks (backup/restore, replication to ensure clustering when a server goes down, Ad Hoc reporting capabilities, and availability of data). The SQL Server 2005 Express Edition was created for single-server scenarios; hence, if you are expecting loads and loads of requests per day, a more enterprise class employing one or more computers for specific tasks will be needed for an N-Tier (Multi-server) scenario.

In the tools scenario, it is "baked" right into the tool set of Visual Basic, C# and ASP.NET TOOLS, allowing easy interaction between your application and data store. ADO.NET acts as "bridge" between the code and the database, administering for initial handshakes, execution of commands (INSERT, UPDATE, DELETE, etc.) and queries. Tables are the building blocks of a relational database. They are collections of columns and instances of columns, called rows or records. Columns are defined by their names, data types and other special properties (i.e. automatic numbering sequence, can it be empty, relationship with other tables, default values, etc.). The intersections between rows and columns are called data fields.

To create a database, open your Visual Web Developer and add new item using SQL database template. The Database Explorer will show objects in the database, right click on Tables and add a table. Define columns, data types and other properties of the table. To populate your table, right click on the Table and select Show Table Data option. Upon saving data, an error will occur if data is in an incorrect format. Data constraints enforce data integrity by restricting allowable data to be inserted in the data fields.

You can go through SQL Server Help Files and look up data types to check on what range of values can fit the different data types available. Determine and select which is most appropriate for your application, because too large means wasted space, too small produces artificial ceiling, and incorrect data types requires conversion, making reporting more difficult. Another important thing is the identity column, a special property used to automatically number a field based on previous existing rows, either increasing or descending, depending on your specifications, making each row distinct from the other.

To create identity columns, choose a column on a given table; modify column properties, specifically the identity specification, by selecting YES. Define Identity Increment (+ values for increment, - for decrement), and the Identity Seed (initial value). Identity numbers are not reused, even when a row is deleted, since it may potentially orphan rows on other tables (when using keys). Keys are used to link database tables, making them relational; they can either be Primary Key or a Foreign Key.

Primary Keys uniquely identify a single row of a table and cannot be empty. Foreign Keys, on the other hand, link a row of data from a second table to the primary key of the first table. A table can have only one Primary Key, but can have one or more Foreign Key/s. Information that is automatically set is the Enforce Key Constraint, which enables a prompt for invalid or missing data. Normalization or the process used to split up non-relational tables converting their flat-file formats into relational, is a series of steps, and the more the steps, the more normalized the tables become; but, it is not necessary to memorize these steps, it will come out naturally with practice.

Too much normalization, however, complicates things even more. Hence you need to de-normalize your database, into something comfortable for use. The video tutorials are indeed very user-friendly and really suit beginners. It offers step-by-step instructions that are very useful in on-hand practice. With more of these and lots of practice, anybody can develop his or her own applications in no time. References: Microsoft. (2011). What is a Database? 2006. Retrieved May 9, 2011, from http://www.asp.net/sql-server/videos/what-is-a-database.

Microsoft. (2011). Understanding Database Tables and Records 2006. Retrieved May 9, 2011, from http://www.asp.net/sql-server/videos/understanding-database-tables-and-records Microsoft. (2011). More about Column Data Types and Other Properties 2006. Retrieved May 9, 2011, from http://www.asp.net/sql-server/videos/more-about-column-data-types-and-other-properties Microsoft. (2011). Designing Relational Database Tables 2006. Retrieved May 9, 2011, from http://www.asp.net/sql-server/videos/designing-relational-database-tables