30. 09. 10
There are countless flavours of databases, and you would have to be specific about what kind of database you’re talking about. I have honestly extensive knowledge of the MySQL Database, which is an extremely common DB. Most databases are like MySQL in that they operate in “transactions”: steps that change or return information about the database, and which can be run one at a time. Here are some examples:
MAKE TABLE – a database comprises multiple tables, which can be roughly thought of as spreadsheets, each column containing a particular attribute of the table, and each row containing an instance of the “schema,” the set of all attributes of a table. For example, you might have a table for Students. The Student table has a column for each attribute: name, student ID, age, etc. Each row has a value for each of these columns. When you make a table, you give it a name (like Students) and specify the names and types of every attribute of the table (String name, int studentID, int age, etc.)
INSERT – insertion is the transaction which, as you might guess, inserts a row into a particular table. Your tables only contain rows which you insert into them, so this is a very common transaction. You must specify every attribute value for each row you insert (such as “John Smith,” 207793, 18).
SELECT – probably the most commonly used transaction, selection is used to look up a row or row(s). Usually you specify some criteria the row(s) must satisfy: name=”John Smith”… maybe age >= 18. Selection is why databases exist.
There are, of course, a number of features that make databases much more complex, but usually you can easily use a database at this elementary level. To get started, just look up the database (also known as a Database Management System, or DBMS) and go through its tutorial to set it up. Be forewarned: sometimes setting up a database can be confusing.
There you go, excellent luck! The answer before mine is a excellent response if you’re looking to design anything but a simple system, but since you’re asking how databases work, I figure you mostly want to experiment and learn about it, and maybe use it for a simple task.
Often abbreviated DB. A collection of information organized in such a way that a computer program can quickly select desired pieces of data.
You can reckon of a database as an electronic filing system.
Steps to make database
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1. Analyze your requirements
2. Divide your requirements into fixed and variable For example : Employee information in a Payroll database are Fixed and commonly known as Master Information. whereas monthly attendence is variable type information and needs to be updated at regular interval viz. daily/Periodic
3. Reckon of fields in master tables (master tables may be more than 1) like in Inventory management system (Product master/Supplier master/customer master) and Transaction Tables (Goods Received table / Goods Issued table / Goods Returns Table etc.)
Avoid recording duplicate information in database tables like in Goods Issued Table no need to store supplier id since that can be easily retrieved from product table.
Establish a relationship like one-to-many - One record in the master table with multiple records in the transaction table.
For example : Item no. WashPowder001 in the Product table may have many records in the Goods Issued table so the join key would be Item code.
