Chapter9 - Database

9.01 Databases

Single-table databases

A database is a structured collection of data that allows people to extract information in a way that meets their needs.

A single-table database contains only one table. A table consists of many records.

1. each record is a row in the table
2. each field is a column in the table.

Data is often validated when input into a field.

Basic data types

A data type classifies how the data is stored, displayed and the operations that can be performed on the stored value. Each field requires a data type to be selected.

Primary keys

The primary key is a field that uniquely identifies the record. Each primary key contains a unique value; it must contain data values that are never repeated in the table.

Structured Query Language

Structured Query Language (SQL) is the standard query language for writing scripts to obtain information from a database. An SQL script is a list of SQL commands that perform a given task.