This is the beginning of a series of personal tutorials l’ll be giving on my blog about Database and Sql development. I’ll write this tutorial for the following many weeks on various aspects of database and sql. I don’t have any laid out format so l’ll just talk about anything that comes to mind about database during each week’s tutorial but l’m going to do my best to go from bottom up. That’s from basic to more complex stuff.
So for today, let’s try to get general information about database. What is a database? A database can be any thing that keeps record of stuff. For example, you have a notebook that you use to keep record of the calories you consume every day or the miles of jogging you do every day. That notebook can be considered your database because it keeps record of your activities and you can go back and look up different records on different days. This simple idea is transformed into tools or applications that are referred to as database systems in the IT world. There are many database systems, some are commercial and others are open source. Examples of database systems are mysql, Microsoft SQL server, oracle, Microsoft access and many more. All these database systems have a common programming language that is used in manipulating or storing data in them. This language is called SQL, Which stands for Structured Query Language. SQL comes in slightly different flavours for working with different database systems but the basic idea or construct for the language is the same across different database systems. SQL is traditionally a non-procedural language. That is, the language is concerned about “What” not “how”. There is a version of SQL which is procedural and this is called PL/SQL, where PL stands for procedural language. The Microsoft version of SQL is called TSQL, which stands for Transact Structural Query Language.
Another term of interest is Data warehouse. What is a data warehouse? A data warehouse is a database as well, created by organizations to record data over some period of time. It can be used to analyse performance and other business interests. For example, a company can create a data warehouse of all the sales in the united states over two years. The company can use this data warehouse to perform analysis like, in which states were a particular product sold most, which gender group bought a particular product most. This can help the company to make decisions like where to advertise most or which age group to target in their advertisements. There are tools use in all these analysis, example SSAS, component of Microsoft Sql server 2008 R2. etc. I’ll not be delving much into most of the technical side of these analyses but l’ll do my best to give a general idea about how these tools work if necessary. I’ll concentrate more on SQL itself because once you know SQL, you can easily adapt to the various flavours, but as we go deeper into the tutorial in the coming weeks, l’ll start work on TSQL as the main flavour for the tutorial, I’ll use MySQL and Microsoft SQL server 2008 R2 as the main Relational Database Management systems for this tutorial.
Another term of Interest will be RDMS, relational database management system: These are database management systems that store records using tables that are related to each other. A table in a database contains rows and columns. Tables are representatives of entities that the organization needs to keep information about. An entity is simply an object in the real world which is of interest to an organization. Entities have attributes or named properties that further provide meaning to the entity. An example of an entity is a student. Some attributes about the entity student will be, student id, age, first name, last name etc.
Taking the example of a student as an entity, we will have a table name student in the database and this table will have different columns depicting each of the attribute of the student such as student id, first name, last name etc.
I have to caution anyone following this tutorial to reference a book online or get a hard copy of a good database book to use as the main source of learning database design and development. This tutorial is not in depth and simply meant to quickly brush over database development and I’m not using any book, so I’m likely to make mistakes at any point. I’m writing this tutorial directly from my brain based on my studies of database a little while ago in school.
In the next tutorial, l’ll go over different levels of database design.
