Introduction to Structured Query Language (SQL) – Part – 1

History of Structured Query Language (SQL)

This article tries to put emphasis on the Structured Query Language (SQL), from both the aspects of extensive as well as expansive ways. Expansive way, meaning that it is applied at numerous stages of database communication, starting from a simple Admission Form Combo-Box right up to High Dimensions communications among the mainframes. Structured Query Language (SQL) is extensively applied in nearly every single Database Management System (DBMS) which supports Structured Query Language (SQL) commands for communication. The cause for this level of recognition is partly described by means of the quantity of effort which went into the notion as well as enlargement of the ethics.

Existing Dialects of the Structured Query Language (SQL)

Structured Query Language (SQL) became a standard of the American National Standards Institute (ANSI) in 1986 as well as of the International Organization for Standardization (ISO) in 1987. From that time onwards, the standard has been revised to include a superior set of features. The various standards of Structured Query Language (SQL) are as follows:-

• SQL: 1986

• SQL: 1989

• SQL: 1992

• SQL: 1999

• SQL: 2003

• SQL: 2006

• SQL: 2008

• SQL: 2011

The huge percentage of the language has not been modified through the abovementioned updates. An individual can be gainful from the information that nearly every code which was written according to Structured Query Language (SQL) standards of 1989 is still flawlessly functioning. In other words, as a fresh learner of Structured Query Language (SQL), starts with the newer versions of the Structured Query Language (SQL), they need not to worry about the too much of enhancement in the technical part of the coding.

Most Database Management Systems are planned to encounter the SQL 1992 standard. Practically every material in this article was accessible in the previous versions too. As many of the innovative features of SQL 1992 are however still needed to be applied by Database Management Systems (DBMS) vendors, there has been a bit pressure for a fresh innovative version of the standard. Nevertheless a SQL 1999 standard was designed to address cutting-edge issues in Structured Query Language (SQL). The entire essential functions of Structured Query Language (SQL), like as inserting, selecting as well as altering information, are alike.

There are three (3) parts where there is up-to-date improvement in Structured Query Language (SQL) standards. Mainly it involves refining the Internet access to information, mostly to encounter the necessities of the developing Extensible Markup Language (XML) standards. Additionally, the integration of Structured Query Language (SQL) with Java either through Sun’s Java Database Connectivity (JDBC) or through the internal implementations. And lastly, the group which establishes Structured Query Language (SQL) standards is considering by what means to incorporate the object oriented software development models.

What is Structured Query Language (SQL)?

The Structured Query Language is normally shortened to SQL in addition it is pronounced as “SEQUEL”, is not an orthodox computer programming language in the regular sense of the expression. It allows the end users to access information in Relational Database Management Systems (DBMSs). Structured Query Language (SQL) is about information as well as output; every single Structured Query Language (SQL) command provides a result, whether that result is an inquiry, or an update to any existing information or simple formation of a database table or relation. Structured Query Language (SQL) is most frequently castoff to address the relational database, which is what a number of individuals mentions to as a Structured Query Language (SQL) database. Therefore in brief the Structured Query Language (SQL) can be defined as follows:

• SQL stands for Structured Query Language

• Structured Query Language (SQL) permits an individual to access a database

• Structured Query Language (SQL) can execute queries against a database

• Structured Query Language (SQL) can retrieve data from a database

• Structured Query Language (SQL) can insert new records in a database

• Structured Query Language (SQL) can delete records from a database

• Structured Query Language (SQL) can update records in a database

• Structured Query Language (SQL) is easy to learn

Forming a Database

Numerous database systems have graphical user interfaces (GUI) that permit the database designers as well as end users to build, alter and to interact with the primary Database Management System (DBMS). On the other hand, for the purposes of this article every communication with the Database Management System (DBMS) will be done by means of Structured Query Language (SQL) statements instead of menus.

Structured Query Language Statements

There are three (3) sets of statements present in the Structured Query Language (SQL) which are mentioned below: –

1. Data Definition Language (DDL)

2. Data Manipulation Language (DML) and

3. Transaction Control Language (TCL)

Characteristics of Structured Query Language Statements

In this section an individual can see that Structured Query Language (SQL) statements comply with a number of rudimentary guidelines:

• Structured Query Language (SQL) key words are not generally case sensitive, however in this article all the statements like SELECT, UPDATE etc. are presented in upper case format.

• Variable as well as parameter names are presented as lower case in this article.

• New line characters are overlooked in Structured Query Language (SQL), so a statement can be written all on one line otherwise can be broken up over a number of lines for the sake of simplicity.

• Several Database Management Systems (DBMSs) are assumed to have Structured Query Language (SQL) statements finished with a semi-colon (;) character.

In the upcoming part we will be discussing how to make use of data definition language (DDL) in structured query language (SQL), in what manner to form a table or relation and in what manner to alter a table or relation.