Databases

Data types, fields, queries, records, tables, validation, primary keys and the database concept.

Primary Key (Primary Keyword)

A primary key, also known as primary keyword, is a key in a relational database which is specific for each record.  It is a unique attribute, like a driver’s license number, telephone number with area code, or vehicle identification number (VIN).  A relational database can only have one primary key.  Primary keys are usually displayed …

Read morePrimary Key (Primary Keyword)

What is a Database?

A database is any collection of information that has been systematised for quick searching and retrieval via the use of a computer.  Databases are intended to provide the means for the modification, deletion, storage, and retrieval of data in connection with different operations.  A database management system (DBMS) utilises queries to pull out information from the database. A database can …

Read moreWhat is a Database?

Database Queries

A query is a way of requesting information from the database. A database query can be either a select query or an action query. A select query is a query for retrieving data, while an action query requests additional actions to be performed on the data, like deletion, insertion, and updating. For example, a manager …

Read moreDatabase Queries

Database Fields

Database A database is a set of data arranged in a way that a computer program can immediately choose required portions of data.  It is often called a DB. A common database can be compared to a filing system which is arranged by fields, records, and files.  A field is a specific piece of data, …

Read moreDatabase Fields

Database Table

A relational database is made up of different components. The most important of these is the table. All the data in the database is stored in the database table.  Without tables, there would not be much need for relational databases at all. Information on a single subject is placed in order as rows and columns in …

Read moreDatabase Table

DBMS

Candidates should be able to: describe how a DBMS allows the separation of data from applications and why this is desirable describe the principal features of a DBMS and how they can be used to create customised data handling applications. What is a DBMS? A Database Management System (DBMS) is used to manage a database. …

Read moreDBMS

Database Validation

It is imperative that data is entered correctly in a database.  An automated database has the benefit of including automatic checks in order to prevent incorrect data from being recorded into the database.  This is a process which isn’t available in a manual database. Validation is a process whereby the data entered in the database is …

Read moreDatabase Validation

Database Data Types

A database data type refers to the format of data storage that can hold a distinct type or range of values.  When computer programs store data in variables, each variable must be designated a distinct data type.  Some common data types are as follows: integers, characters, strings, floating point numbers and arrays.  More specific data …

Read moreDatabase Data Types

Database Record

A database record is collection of fields about the same person, item, or object in a database. The database record can be thought of as a row of information within a database table. The Database A database is a set of data arranged in a way that a computer program can immediately choose required portions …

Read moreDatabase Record

What is a Relational Database?

Candidates should be able to: understand the relationship between entities and tables understand the components of a relational database, such as tables, forms, queries, reports and modules understand the use of logical operators in framing database queries explain the use of key fields to connect tables and avoid data redundancy describe methods of validating data …

Read moreWhat is a Relational Database?

The DBMS

Candidates should be able to: describe how a DBMS allows the separation of data from applications and why this is desirable describe the principal features of a DBMS and how they can be used to create customised data handling applications. What is a DBMS? A Database Management System (DBMS) is used to manage a database. …

Read moreThe DBMS

The Database Concept

Candidates should be able to: describe a database as a persistent organised store of data explain the use of data handling software to create, maintain and interrogate a database. What is a database? A database is a persistent, organised store of related data. A database is persistent because the data and structures are stored in …

Read moreThe Database Concept