Introduction To SQL: Types Of Commands In It
To begin with, SQL (Structured Query Language) is a data query language that is useful in managing and storing data in a Relational DBMS. It helps in writing queries in a database and is one of the most demanding skills in the current world. To further know about its workings and functionalities, one can visit SQL Online Training.
Commands In SQL
SQL consists of five types of commands to manipulate the stored data in RDBMS.
· DDL: Data Definition Language- The commands are responsible for modifying the structure of the table. They are auto-committed and save all the changes in the database permanently. Examples are- Create, Alter, truncate, Drop, Rename.
· DML: Data Manipulation Language- These commands help in manipulating the data inside a table. In addition, these commands are not auto committed and they can roll back. Examples are- Insert, Upgrade, Delete, Merge.
· TCL: Transaction Control Language- TCL commands are responsible for keeping a check on other commands. In addition, they can roll back the changes into their original state. Examples are- Commit, Rollback, Savepoint.
· DCL: Data Control Language- DLC languages help in granting or taking back the authority from a user. It includes two commands that are Revoke and Grant.
· DQL: Data Query Language- These commands are responsible for fetching data from tables. It consists of only one command is Select.
Features Of SQL
SQL is an open-source programming language and it provides high performance for dealing with highly transactional and high usage database systems. In addition, it is compatible with multiple database systems such as MS Access, Microsoft SQL Server, MySQL, and many more. Moreover, it is a scalable and flexible language and it helps in creating a new table or dropping a previously created table easily.
Above all, SQL is capable of handling large records and managing multiple transactions at once. It is a highly secure platform that provides permissions on tables, procedures, and views. Due to its significant features, it is useful in various organizations to access a database. Several institutions provide SQL Training in Noida and one can enrol in the to learn it. Apart from these, given below are some of the features of SQL functions.
· They are easy to implement as they use simple high-level, strongly typed language.
· They are much more reliable than the equivalent external functions.
· SQL scalar functions return a scalar value.
· The table functions return a table result set.
· In addition, it helps in accessing SQLSTATE and SQLCODE values.
· They can be invoked from triggers.
