SQL Commands stands for Structured Query Language Commands. In the era when massive volumes of data are generated, there is a constant need to manage data in databases. SQL is the foundation of relational databases, which are one of the most common databases. As a result, SQL abilities are required in almost every employment role.
SQL is the industry standard for database management. It is a database language that allows you to manage and retrieve data from relational databases.
SQL plays a very important due for the following reasons :
- It enables users to access data stored in DBMS
- It helps describe data in a better way
- It allows to build a view, a function in the database, etc
Types of SQL Commands
SQL commands are categorized broadly into five categories –
- DDL: It stands for Data Definition Language. It is used to design database structures. It handles schema descriptions and is used to construct and modify structure.
Different DDL commands are: CREATE command, DROP command, Alter command, TRUNCATE command, etc.
- DML: It stands for Data Manipulation Language. It’s the part of the SQL statement that regulates who has access to data and the database.
Different DML commands are: INSERT command, UPDATE command, DELETE command, etc.
- DCL: It stands for Data Control Language. It is a query language that allows users to retrieve and edit data held in a database.
Different DCL commands are: GRANT command, REVOKE command, etc.
- TCL: It stands for Transaction Control Language. It is used in the database to manage transactions. It allows for combining statements into logical transactions.
Different TCL commands are: COMMIT command, ROLLBACK command, SAVEPOINT command, etc.
- DQL: It stands for Data Query Language. Its goal is to return a schema relation depending on the query supplied to it.