This is SQL tutorial for beginners to help them in understanding the basic to advanced concepts of SQL languages.
This tutorial will be a quick start with SQL for beginners.Similarly, This is an SQL quick reference guide for experienced SQL programmer
SQL, which stands for Structured Query Language, is a relational language implemented universally. The language is based on the relational model; however, it isn’t an exact implementation. The relational model offers important theoretical foundations of a relational database, while the core task of SQL is to support the physical foundations of that database.
In simple terms, the Structured Query Language is generally used to “talk” to any database server. Deployed as the front-end to several databases, including Oracle, MySQL, Sybase and PostgreSQL. SQL is the universal standard language to access, manage and maintain databases.
SQL is the universal standard language to access, manage and maintain databases.
The language is a bit different when compared to other widely-used languages like Java, COBOL, and C, which are procedural languages. Procedural languages define how the operations of an application should be executed and the order in which they are executed. On the other hand, non-procedural languages focus more on the outcomes of an operation; the order in which the operations are executed is determined by the underlying software environment. However, it doesn’t really mean that SQL does not support procedural functionality at all. For instance, several stored procedures, which were integrated into different RDBMS products a few years back, comply to the SQL:2006 standards and, they do offer procedural-like capabilities. Several extensions, including Transact in Microsoft SQL Server and Sybase, were added to the SQL to generate procedure-like capabilities.
However, the SQL still falls short on many fundamental programming features and functionalities as opposed to the majority of other programming languages. As a result, SQL is a misnomer and the language is generally considered as a data sublanguage since it is frequently used in conjunction with other computer languages like Java and C, languages that are not meant to manipulate data in a database. Hence SQL is used in associated with such languages to access data efficiently.
In-a-Nutshell – SQL Supports three subsystems, data access, data description, and privileges.SQLIs optimized for specific data arrangements
SQL is a standard universal language and is compliant with ANSI, but it is available in multiple versions. However, each different version maintains compliance with the ANSI standard by support all basic commands similarly, such as UPDATE, SELECT, INSERT, DELETE, WHERE).
Note: The majority of database applications have their personal proprietary extensions in conjunction with the SQL standard.
RDBMS (Relational Database Management System) is the underpinning of several database systems like Oracle, MS SQL Server, MySQL, IBM DB2 and Microsoft Access.
A relational database is structured to identify relations between stored information items.
The data is structured in objects called tables. Tables are formally described and contain rows and columns assembled with related data items.