Programming sites is performed in order to create some useful functionality. Working with databases is one of the most important components of programming sites of a dynamic type. Whether it’s creating pages on the fly or responding to the actions of website visitors, interaction with databases is always required.
Databases for sites (DB) are used to store various information and, simplistically, represent a certain set of interconnected tables. The sizes of the tables in the database are different, their number is arbitrary. It is in the databases that the information required for the site’s work is stored on the server, for example, customer information, product catalog, statistical data, etc.
Programming dynamic type sites is performed using various scripts, usually divided into server and client. Programming sites using server scripts allows you to process data entered by website visitors into web forms, generate dynamic pages, send and receive cookies. To obtain the information required when performing such actions, server-side scripts access databases. The script call to the database is called a query.
To build database queries, SQL (Structured Query Language) is widely used – the “structured query language”. Using SQL, you can add, delete, edit records in database tables, select data in accordance with various conditions, sort data, and much more.
In website programming, database management is carried out using client-server database management systems (DBMS), such as Oracle, MS SQL Server, PostgreSQL, MySQL, etc. Client-server DBMSs process requests centrally, their advantages include ensuring high reliability of databases High availability and high security.
MySQL DBMS is a free database management system, one of the most frequently used in website programming. MySQL DBMS supports a large number of existing table types (InnoDB, MyISAM, etc.), and thanks to its open architecture and GPL licensing, new types of tables are constantly appearing in MySQL DBMS. Managing databases using MySQL is very convenient, which has made this system popular and popular.
Microsoft SQL Server relational database management system is supplied by Microsoft on a commercial basis (with the exception of the free Express Edition). This DBMS uses the Transact-SQL query language and is supported by the operating systems of the Windows Desktop / Server family. Microsoft SQL Server DBMS has graphical software for designing and optimizing queries (SQL Management Studio and Studio Express).
Oracle’s object-relational database management system – Oracle Database – runs on Windows, Unix, Linux, MacOS. Oracle Database, unlike MySQL, for example, has a wider scope. Oracle DBMS has high performance, wide functionality, unique technologies (RAC, RAT, etc.). In website programming for small and medium-sized companies it is rarely used due to its high cost. In addition, it is quite difficult to find a hosting with support for this DBMS.
PostgreSQL is a free database management system available for Linux, Solaris / OpenSolaris, Win32, Win x86-64, Mac OS X, FreeBSD, QNX 4.25, QNX 6. It is based on the SQL language. Among the advantages of PostgreSQL are database support of almost unlimited size, the availability of reliable replication mechanisms, easy extensibility, support for a large set of built-in data types, and much more.
Programming sites that interact in various ways with databases includes several basic stages of working with a database: building database queries using SQL, programming scripts to process these queries, and programming modules to display the results of query processing.
The excessive number of hits from sites to databases makes loading sites slower, increases the load on the server. As a result, there may be malfunctions in the sites, up to a complete cessation of access. Reducing the number of queries to the database can reduce the load on the server, as well as reduce the loading time of dynamic pages from the server. Therefore, optimizing the interaction of sites with databases is one of the tasks of professional website programming.