Microsoft Access & Databases

Types of Database Models

Databases store and access data in many ways. For example, companies use databases containing price and product information on an e-commerce site. Website content management systems allow database users to make changes to web content without having technical knowledge. Databases help businesses involved in distribution, logistics, shipping, and inventories. For example, a company may want to store customer data, such as contact details and home addresses, to be modified and updated.

Hierarchal databases are similar to a tree structure with records stored in groups of master and subordinate relationships. There may be a high priority table, e.g. containing customer details and relationships between many subordinate product tables. This model is fast and straightforward to use but only has one-to-many relationships.

Relational databases have data organised in a series of related tables. This type of database is easy to create, add to, and access. Companies use relational databases to manage employee details for different departments, such as employee name, salary, and department details. These details may be related to salary tables and managerial data sets.

Object-orientated databases have data represented by objects. Not all these models support Structured Query Language. SQL is a language used in Microsoft Access when it runs Queries.

Stages of a Database

Stage 1 – Design

The design must be clear and easy to understand. Consider the purpose of the database. How will it output data? What will the result of the database be? How will it serve the needs of the people who access it?

Stage 2 – Creation

Creation involves developing tables, relationships, forms, queries, and reports. This process needs careful attention to ensure a clear understanding of the links between tables and the output of selected databases.

Stage 3 – Data Entry

This stage involves entering information into a database. Data entry is a long, labour-intensive process and requires a skilled user. There are many features in Microsoft Access that can limit the chance of errors occurring, such as data validation methods that only allow specific information entry and input masks where data entered must be of a particular format.

Stage 4 – Data Maintenance

Data maintenance involves adding new information and removing unnecessary data from a database to make it more efficient. This process develops continually as information changes, e.g. contact details of customers or product updates.

Stage 5 – Information Retrieval

Information is retrieved and organised using queries, forms, and reports. Users may only be allowed to use sections of a database because of restrictions.

Applications of Databases

Databases serve the purpose of dynamic websites where data is retrieved and updated for information such as product details or prices. Databases manage mailing lists where e-mail details are stored. These databases can then be updated when contact details change.

For instance, when a customer enters contact details such as name, address, e-mail, and date of birth into a shopping website, this data is automatically retrieved and updated using company databases. This information relates to products purchased by that customer and is stored in the organisation's databases.

Website content management systems use databases where users without technical skills can edit information, e.g. product sales details. The user may input data without having to know coding languages. It makes data entry more effective and efficient.

Customer Relationship Management Systems uses databases to store and retrieve customer details in an organisation. A company can use information such as name and address. This information can then be updated whenever customers' details change.

This system may apply to a hotel business, for instance, where staff members use an established content management system. A client database may store guests' contact details. Information about the amount charged, length of stay and room stayed in may also be included in separate tables. This information can then be changed and updated as different guests arrive and leave the hotel.

Enterprise Resource Planning Systems are used in organisations regularly to perform functions such as accounting or finance. This database type may project sales forecasts, develop a company's budget, or track a department's financial position within a company. For instance, the accounts department may use this type of database to calculate the profit or loss of a company in a given year.