SQL Database Course And Certification
What is SQL?
SQL (Structured Query Language), pronounced as "sequel" is a domain-specific language that is used in programming and it is designed to be used to manage data held in a relational database management systems (RDBMS), it can also be used for stream processing in a relational data stream management system (RDSMS). SQL is especially useful in handling structured data, for example, data organizing relations among different entities and variables.
SQL presents two major advantages over previous read-write APIs such as VSAM or ISAM. It initially introduced the concept of accessing many records with one unique command. Then, it eradicates the need to specify how to reach a data record, e.g. with or without an index.
SQL is primarily based upon relational algebra and calculus that are tuple relational, SQL is made up of many types of statements, which may be informally categorized as sub-languages, usually, a data query language (DQL), a data definition language (DDL), data manipulation language (DML) and a data control language (DCL).
The scope of SQL comprises of data query, data manipulation (eg, insert, update and delete), data definition (which are, the creation and modification of database schema), and data access control. Although SQL is primarily a declarative language (4GL), it also includes procedural elements.
Components of SQL
1. Data Definition Language: The Data Definition Language (DDL) contains commands that are less frequently used. DDL commands modify the actual structure of a database, rather than the database’s contents. Examples of commonly used DDL commands include those used to generate a new database table (CREATE TABLE), modify the structure of a database table (ALTER TABLE), and delete a database table (DROP TABLE).
2. Data Manipulation Language: The four most common DML commands retrieve information from a database (the SELECT) command, add new information to a database (the INSERT command), modify information currently stored in a database (the UPDATE command), and remove information from a database (the DELETE command). It contains the subset of SQL commands used most frequently — those that simply manipulate the contents of a database in some form.
3. Data Control Language: The Data Control Language (DCL) is used to manage user access to databases. It consists of two commands: the GRANT command, used to add database permissions for a user, and the REVOKE command, used to remove existing permissions. These two commands form the core of the relational database security model.
4. Query Language: The query language is also a part of DML, and is used to retrieve data from a table using Select command and other key commands.
5. Transaction Control Language: Transactional statements include commit, rollback and save points. the session control statement is used to change session-level parameters, like default date formats and numeric formats. The system control statements are used to change system-wide parameters, like memory allocation.
Features and Characteristics of SQL
1. High Performance: SQL from inception provides high-performance programming capability for extremely transactional, complicated and heavy workload and high usage database system. SQL programming presents you with various ways to describe your data more analytically.
2. High Availability: SQL is compatible with various databases like Microsoft SQL Server, MS Access, MySQL, Oracle Database, SAP Adaptive Server, SAP HANA, etc. All of these relational database management systems have support for SQL and it is very easy to develop an application extension for procedural programming and various other functions which are added features, therefore, converting SQL into a very powerful tool.
3. Scalability and Flexibility: SQL provides Flexibility and Scalability. It is very easy to create new tables and previously created unused tables can be dropped or deleted in the database.
4. Robust Transactional Support: With SQL, programming can handle large records of data and manage various transactions.
5. High Security: It is very easy to implement permissions on tables, procedures, and views therefore SQL gives security to your data.
6. Comprehensive Application Development: SQL is used by many software developers to develop apps that access a database. No matter what is the size of an organization or business is, SQL works for every small or large organization.
7. Management Ease: SQL is used in almost every relational database management system, and it presents common commands that help to manage large amounts of data from a database very quickly and efficiently.
8. Open Source: SQL is an open-source programming language for developing a relational database management system
Benefits and Advantages of SQL
1. High speed: Using the SQL queries, the software developer can efficiently and quickly retrieve a large number of records from a database.
2. No coding needed: In conventional SQL, it is very easy to manage the database system. It does not expect a large amount of code to manage the database system.
3. Well defined standards: Long established standards that are used by the SQL databases are also used by ISO and ANSI.
4. Portability: SQL can be used in PCs, laptops, servers and even on some mobile phones.
5. Interactive language: SQL is a domain language that is used to interact with the database. It is also used to receive solutions to complex questions in seconds.
6. Multiple data view: Using the SQL language, the developer can make different views of the structure of the database.
Why Study SQL?
1. Data Mining: Using basic queries you can identify specific data at time intervals, view update events, monitor table activity, and much more.
2. High Demand: You shouldn’t have a problem finding a job as an SQL programmer. There are more SQL programming jobs than any other type of programming language.
3. Data Manipulation: SQL is particularly effective at data manipulation,, because it allows you to see the exact data and how it works, you’ll have an easier time testing and manipulating the data.
4. Databases And Servers: If you plan on managing servers, or creating your own server, SQL programming language will most certainly prove useful.
5. Increase Your Earning Potential
6. Job Opportunities and Career Advancement