2.6 Databases

Record

A data structure composed of fields. For example, an employee record could be created for each employee and could contain fields, such as employee first name, employee last name, job, salary, and hire date.

Foreign Key

A foreign key is a column or group of columns in one table that references the primary key column of another table. The foreign key and primary key establish the relationships between tables and are used to join two tables together when using the Select statement. The values in the foreign key column(s) must exist in the primary key columns(s) that they reference or they will be NULL.

Primary Key

A relational database table column or set of columns that uniquely identify each row (record) in a table.

Field

A single collection of data that is at least one byte in size. Fields are used to store information in forms, spreadsheets, files, and databases. Examples of fields include EMPLOYEE FIRST NAME, EMPLOYEE LAST NAME, SALARY, and ADDRESS

Form

An object that is designed for users to input information. Forms contain fields, user prompts, and other features that make entering information easier and more efficient.

Big Data

Extremely large sets of data that, when analyzed, can reveal patterns and trends.

Database

Information organized in a central location or file so a computer can efficiently insert, update, delete, retrieve, and process it.

SQL

Structured Query Language. A computer language that is used to retrieve and interact with data in a database.

Query

The process of retrieving information from a database. Information can be retrieved from a database by using a query language, such as SQL, or by using a database application that retrieves information based on user-selected options.

Relational Database

A database structure where data is stored in tables and a logical relationship exists among tables and columns in a one-to-one, one-to-many, or many-to-many form.

NoSQL

A type of database that does not use SQL. NoSQL databases are generally better for unstructured data, such as big data.

Table

Information organized in rows and columns.