Databases

Introduction

Dynamic websites are stored all the data (content) in databases. This is where HTML can be seen as the structure of the static data.

Concepts

A database is an organized collection of data that allows Search Issues and Sort. Except that only the read from the database you also need to write to happen and administrative measures create, delete Edit in it.

The scheme is in its simplest form, a two-dimensional Tablewith rows and columns. In these tables for there are usually several, called each line of mail and each cell in the row is a bar. Each field has a defined Field Type, for example, text string, numeric value or Boolean expression.

relational database

A table can have one or more Relations with other tables.
Databases tend to also go by the name of the relational database and that's when relationships of tables created that magic occurs. One can e.g. in theory, ask questions about the people who run the red car and the enforcement history. In fact, of the Personal Data Act (Privacy Act) this and it needed special permission for such relationships. For this reason, it is often used aliases (compare with username) iställer of identifiable individuals.


Examples of how to create a table.

When communicating with a database that uses a language SQL (Structured Query Language) used to extract and manipulating data. An example of how to set a question may be to show Name, Address, Postcode, Town from the Customers table where the Customers table's field Location to be Eskilstuna...

SELECT name, address, postcode, city FROM customers WHERE Kunder.Ort='Eskilstuna';

Read more

Please study http://www.w3schools.com/sql/sql_syntax.asp to learn more about SQL commands.