What are the 5 basic SQL queries?

SQL is a database language designed for the retrieval and management of data in a relational database.

Table of Contents Show

Why Use SQL?
Brief History of SQL
Types of SQL
What is DDL?
Examples of DCL commands:
What are the 4 basic commands in SQL?
What is basic SQL query?
What are the 5 SQL statement types?
How do I start SQL basic?
What are the 5 basic SQL commands?
What are types of SQL?
Is SQL a syntax?
What is the primary key?
What is DML and DDL?
What are the 3 types of SQL commands?

SQL is the standard language for database management. All the RDBMS systems like MySQL, MS Access, Oracle, Sybase, Postgres, and SQL Server use SQL as their standard database language. SQL programming language uses various commands for different operations. We will learn about the like DCL, TCL, DQL, DDL and DML commands in SQL with examples.

In this SQL commands in DBMS tutorial, you will learn:

Why Use SQL?

Here, are important reasons for using SQL

It helps users to access data in the RDBMS system.
It helps you to describe the data.
It allows you to define the data in a database and manipulate that specific data.
With the help of SQL commands in DBMS, you can create and drop databases and tables.
SQL offers you to use the function in a database, create a view, and stored procedure.
You can set permissions on tables, procedures, and views.

Brief History of SQL

Here, are important landmarks from the history of SQL:

1970 – Dr. Edgar F. “Ted” Codd described a relational model for databases.
1974 – Structured Query Language appeared.
1978 – IBM released a product called System/R.
1986 – IBM developed the prototype of a relational database, which is standardized by ANSI.
1989- First ever version launched of SQL
1999 – SQL 3 launched with features like triggers, object-orientation, etc.
SQL2003- window functions, XML-related features, etc.
SQL2006- Support for XML Query Language
SQL2011-improved support for temporal databases

Types of SQL

Here are five types of widely used SQL queries.

Data Definition Language (DDL)
Data Manipulation Language (DML)
Data Control Language(DCL)
Transaction Control Language(TCL)
Data Query Language (DQL)

Types of SQL

Let see each of them in detail:

What is DDL?

Data Definition Language helps you to define the database structure or schema. Let’s learn about DDL commands with syntax.

Five types of DDL commands in SQL are:

CREATE

CREATE statements is used to define the database structure schema:

Syntax:

CREATE TABLE TABLE_NAME (COLUMN_NAME DATATYPES[,....]);

For example:

Create database university; Create table students; Create view for_students;

DROP

Drops commands remove tables and databases from RDBMS.

Syntax

DROP TABLE ;

For example:

Drop object_type object_name; Drop database university; Drop table student;

ALTER

Alters command allows you to alter the structure of the database.

Syntax:

To add a new column in the table

ALTER TABLE table_name ADD column_name COLUMN-definition;

To modify an existing column in the table:

ALTER TABLE MODIFY(COLUMN DEFINITION....);

For example:

Alter table guru99 add subject varchar;

TRUNCATE:

This command used to delete all the rows from the table and free the space containing the table.

Syntax:

TRUNCATE TABLE table_name;

Example:

TRUNCATE table students;

Data Manipulation Language (DML) allows you to modify the database instance by inserting, modifying, and deleting its data. It is responsible for performing all types of data modification in a database.

There are three basic constructs which allow database program and user to enter data and information are:

Here are some important DML commands in SQL:

INSERT:

This is a statement is a SQL query. This command is used to insert data into the row of a table.

Syntax:

INSERT INTO TABLE_NAME (col1, col2, col3,.... col N) VALUES (value1, value2, value3, .... valueN); Or INSERT INTO TABLE_NAME VALUES (value1, value2, value3, .... valueN);

For example:

INSERT INTO students (RollNo, FIrstName, LastName) VALUES ('60', 'Tom', Erichsen');

UPDATE:

This command is used to update or modify the value of a column in the table.

Syntax:

UPDATE table_name SET [column_name1= value1,...column_nameN = valueN] [WHERE CONDITION]

For example:

UPDATE students SET FirstName = 'Jhon', LastName= 'Wick' WHERE StudID = 3;

DELETE:

This command is used to remove one or more rows from a table.

Syntax:

DELETE FROM table_name [WHERE condition];

For example:

DELETE FROM students WHERE FirstName = 'Jhon';

DCL (Data Control Language) includes commands like GRANT and REVOKE, which are useful to give “rights & permissions.” Other permission controls parameters of the database system.

Examples of DCL commands:

Commands that come under DCL:

Grant:

This command is use to give user access privileges to a database.

Syntax:

GRANT SELECT, UPDATE ON MY_TABLE TO SOME_USER, ANOTHER_USER;

For example:

GRANT SELECT ON Users TO'Tom'@'localhost;

Revoke:

It is useful to back permissions from the user.

Syntax:

REVOKE privilege_nameON object_nameFROM {user_name |PUBLIC |role_name}

For example:

REVOKE SELECT, UPDATE ON student FROM BCA, MCA;

Transaction control language or TCL commands deal with the transaction within the database.

Commit

This command is used to save all the transactions to the database.

Syntax:

Commit;

For example:

DELETE FROM Students WHERE RollNo =25; COMMIT;

Rollback

Rollback command allows you to undo transactions that have not already been saved to the database.

Syntax:

ROLLBACK;

Example:

DELETE FROM Students WHERE RollNo =25;

SAVEPOINT

This command helps you to sets a savepoint within a transaction.

Syntax:

SAVEPOINT SAVEPOINT_NAME;

Example:

SAVEPOINT RollNo;

Data Query Language (DQL) is used to fetch the data from the database. It uses only one command:

SELECT:

This command helps you to select the attribute based on the condition described by the WHERE clause.

Syntax:

SELECT expressions FROM TABLES WHERE conditions;

For example:

SELECT FirstName FROM Student WHERE RollNo > 15;

Summary:

SQL is a database language designed for the retrieval and management of data in a relational database.
It helps users to access data in the RDBMS system
In the year 1974, the term Structured Query Language appeared
Five types of SQL queries are 1) Data Definition Language (DDL) 2) Data Manipulation Language (DML) 3) Data Control Language(DCL) 4) Transaction Control Language(TCL) and, 5) Data Query Language (DQL)
Data Definition Language(DDL) helps you to define the database structure or schema.
Data Manipulation Language (DML) allows you to modify the database instance by inserting, modifying, and deleting its data.
DCL (Data Control Language) includes commands like GRANT and REVOKE, which are useful to give “rights & permissions.”
Transaction control language or TCL commands deal with the transaction within the database.
Data Query Language (DQL) is used to fetch the data from the database.

Sql Basic Commands With Code Examples

In this lesson, we’ll use programming to attempt to solve the Sql Basic Commands puzzle. This is demonstrated by the code below.

Some of The Most Important SQL Commands SELECT - extracts data from a database UPDATE - updates data in a database DELETE - deletes data from a database INSERT INTO - inserts new data into a database CREATE DATABASE - creates a new database ALTER DATABASE - modifies a database CREATE TABLE - creates a new table ALTER TABLE - modifies a table DROP TABLE - deletes a table CREATE INDEX - creates an index (search key) DROP INDEX - deletes an index

The solution to the previously mentioned problem, Sql Basic Commands, can also be found in a different method, which will be discussed further down along with some code examples.

\du /list users and their attributes \conninfo /connection info \l /list databases their owners and other attributes

With numerous examples, we have seen how to resolve the Sql Basic Commands problem.

What are the 4 basic commands in SQL?

There are four basic SQL Operations or SQL Statements.

SELECT – This statement selects data from database tables.
UPDATE – This statement updates existing data into database tables.
INSERT – This statement inserts new data into database tables.
DELETE – This statement deletes existing data from database tables.

What is basic SQL query?

SQL stands for Structured Query Language. SQL commands are the instructions used to communicate with a database to perform tasks, functions, and queries with data. SQL commands can be used to search the database and to do other functions like creating tables, adding data to tables, modifying data, and dropping tables.01-Jan-2020

What are the 5 SQL statement types?

Types of SQL Statements

Data Definition Language (DDL) Statements.
Data Manipulation Language (DML) Statements.
Transaction Control Statements.
Session Control Statements.
System Control Statement.
Embedded SQL Statements.

How do I start SQL basic?

Where to Learn SQL

Master the basics. Start by learning the basic SQL syntax. W3Schools has great SQL tutorials that can help you get familiar with the language.
Take a SQL course. Take a course to build up your SQL knowledge.
Work on real-world projects. Practice with real data + a database.

What are the 5 basic SQL commands?

Some of The Most Important SQL Commands

SELECT – extracts data from a database.
UPDATE – updates data in a database.
DELETE – deletes data from a database.
INSERT INTO – inserts new data into a database.
CREATE DATABASE – creates a new database.
ALTER DATABASE – modifies a database.
CREATE TABLE – creates a new table.

What are types of SQL?

There are five types of SQL commands: DDL, DML, DCL, TCL, and DQL.

Data Definition Language (DDL) DDL changes the structure of the table like creating a table, deleting a table, altering a table, etc.
Data Manipulation Language.
Data Control Language.
Transaction Control Language.
Data Query Language.

Is SQL a syntax?

Syntax is the set of rules by which the elements of a language are correctly combined. SQL syntax is based on English syntax, and uses many of the same elements as Visual Basic for Applications (VBA) syntax.

What is the primary key?

A primary key, also called a primary keyword, is a key in a relational database that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). A relational database must always have one and only one primary key.

What is DML and DDL?

DDL is the acronym for the data definition language. DML is the acronym for the data manipulation language. DDL is used to create database schema and also define constraints as well. DML is used to delete, update and update data in the database.13-Jun-2022

What are the 3 types of SQL commands?

There are 3 main types of commands. DDL (Data Definition Language) commands, DML (Data Manipulation Language) commands, and DCL (Data Control Language) commands.22-Nov-2021