Introduction to Structured Query Language (SQL)

If you are interested to get valuable information about SQL, then you have to read this post “Introduction to Structured Query Language (SQL)” completely, you will get some important ideas about SQL like what is Structured Query Language and how it works. Read the post completely so that no details are left out of you and you will get enough knowledge related to SQL.

SQL stands for Structured Query Language, it is an ANSI (American National Standards Institute) standard language. SQL is pronounced as SEQUEL, the database is operated by it.

Now if you do not know the database, then tell you that the database is a collection of information when a large amount of data i.e. information is stored and kept in a server, It is called a Database. This database is fully organic so that it can be easily opened, managed and updated by an authorized person.

What is Structured Query Language(SQL)?

We already know SQL stands for Structured Query Language is a computer programming language by which Structured Data is managed in a Relational Database (RDMS). In a relational database, the data is kept as a table, and each table contains Rows and Columns, in which the data is stored. That is, SQL is designed in such a way that a large database can be easily managed, the information can be inserted or removed, deleted or retrieved, as well as the database changes.

Data:
It is raw fact through which an object can‘t be identified.
Ex – employee no. name, salary of an employee are individually known as one one data

Information:
Organized collection of related data is known as information through which an object can be clearly identified. It is raw fact through which an object can be identified.
Ex – employee no. name, salary of an employee are individually known as one one data

Data file:
Organized collection of related information is known as a data file.
Ex – sales dept, purchase dept, admin dept of a particular company individually maintains their data file.

NOTE:-
Through data is a raw fact through which an object can‘t be identified but it minimum requirement of data base.

What is the use of Structured Query Language?

As you read above the Structured Query Language (SQL) is used to communicate with databases. The database is managed by SQL, such as making any kind of change in the database, changing or deleting an entry, or putting any information in it.

Data is maintained to keep track of object day-to-day traction. The advantage of database management is to know the assets/liability, profile /loss of an organization. The database has no scope which means it can be implemented on small-scale corporate houses.

Medias to maintain database

There are three different medias are available to maintain database

• Paper or cabinet file
• Spreadsheet
• DBMS: It is basically software responsible to store, retrieve and modify the data of a database on user request.

The primary jobs of the above database are the same i.e. to store data, but there are divided into 4 different categories depending on their storage architectures. These databases are also known as data models or data architectures.
Depending on the support to the databases DBMS is also categorized into 4 different types namely

• NDBMS (Network)
• HDBMS (Hierarchical)
• RDBMS (Relation)
• ORDBMS (Object Relation)

RDBMS is not software typically rather than it is a concept or theory developed by a scientist called DR JOHN E.F.CODD the prescribed 12 diff rules for relation architecture. Any database that supports 6 or more than 6 rules will know as a relational database and to manipulate their software has to be RDBMS type.
It is nothing but the organized collection of two-dimensional tables or relations. The primary advantage of relational architecture supports less data redundancy and more data security.

The above graphics (Employee Table) shows the relational models of architecture. In relation model of architecture always data present in different modules, each module is known as a table has a relationship with another one.

All this work SQL (Structured Query Language) is done by itself. To use SQL, you have to put its software on a computer or laptop with a good configuration, and then connect the database to SQL by IP or system name, after which you will get access to the database so that you can Will be able to work on the database accordingly.

Commands used in Structured Query Language. There are some main commands of SQL, which are used to communicate with relational databases, some of them are as follows.
Data Definition Language(DDL): – The structure of a table is changed by the DDL command, such as preparing, deleting, and modifying the Table, View, Synonyms, Sequence, Index, Type, etc.
To create and manipulate the above objects DDL provides the following statements

• Create
• Alter
• Drop
• Tractate
• Rename

Data Manipulation Language(DML): – Modify the database by the DML command, that is, in a way it is responsible for any kind of change occurring in the database.It is responsible to manipulate the records of a table. To do so DML provides the following statements.

• Insert
• Update
• Delete

Data Control Language(DCL): – The DCL command is used to give or withdraw authority to the database user. It support user concepts or schema concept to protect the object from invalid user. To do so DCL provides the following statement

• Grant
• Remove

Transaction Control Language(TCL): – The TCL command is used only with the DML command. Such as INSERT, DELETE, and UPDATE. Any operation is made in Structured Query Language. The records never are saved and until a save command is issued or a discard command is issued. To do so TCL provides the following statements.

• Commit
• Rollback
• Save point

Data Query Language(DQL): – The dql command is used to fetch data from the database. It is responsible to manipulate to retrieve a data from a table and display to the user. To do so DQL provides a statement called select.

What is the history of SQL?

Structured Query Language programming language was first developed in 1970 by IBM researchers Raymond Boyce and Donald Chamberlin. It was previously called SEQUEL, which was later changed to SQL. SEQUEL was first designed to manage and work with IBM’s Database, System R. After this, in 1979, a company called Relational Software, which later became Oracle Company, took out their modified version according to SQL, which was named Oracle V2. After this, many small changes were made with the passage of time, and database technology was progressed, and then with the introduction of Open Source SQL such as MySQL, etc., its availability became quite accessible to a common user.

Friends, hope you have got the information now that what is Structured Query Language, and if you like this information, then share it with others as well. Thank you for reading the information.

NOTE:

JOHN LARRY ERISSION was the founder of ORACLE.
BRUSH SCOTT was the architecture of ORACLE.

Reference Link

Structured Query Language (SQL) Introduction by Oracle
Structured Query Language (SQL) Introduction by Microsoft