Databases

1. Luke Bissett Databases • Databases are like Excel tables • Database tables consist of columns and rows, each column contains a different type of attribute • Each row corresponds to a single record. • Databases you need to retrieve all records that match certain criteria. • You can update records in bulk • You can perform complex aggregate calculations

2. How we use databases • Use a spreadsheet page such as Microsoft access • Data base can be use in a school for recording names of the student • Can be used on websites • We use databases in shops e.g. check outs, barcodes • Databases can be used on mobile phones e.g. contact list

3. Why We Use Databases!!!! • Organize your data in a logical manner. • Fast and efficient data retrieval • Rapidly retrieve the data you want • Enables you to break data into specific parts. • One enormous task to find specific answers if in text file. • Data remains consistent when you add, update, or delete data. • It is very quick and easy to find information. • It is easy to add new data and to edit or delete old data. • Data can be searched easily • Data can be sorted easily • Data can be imported into other applications. • More than one person can access the same database at the same time • Security may be better than in paper files.

4. The Structure of Databases • Two main structures of a database are tables and Indexes • Tables are the structures that store your data • Each table is composed of a number of fields (columns) • Information would be stored in what we call rows. • Fields in the database has a type associated with it • Common types are text, numeric and blob • Some databases are very strict about the type of data that can be stored in a field