Found 15 Questions For DBMS

What are the types of SQL Queries ?

Updated on 19-Dec-2021 16:56:21
We have four types of SQL Queries: DDL (Data Definition Language): the creation of objects DML (Data Manipulation Language): manipulation of data DCL (Data Control Language): assignment and removal of permissions TCL (Transaction Control Language): saving and restoring changes to a database Let’s look at the different commands under DDL: Command Description CREATE Create objects in the database ALTER Alters the structure of the database object DR... Read More

How can I see all tables in SQL?

Updated on 14-Dec-2021 17:13:39
Different database management systems have different queries to see all the tables. To see all the tables in MYSQL, we would have to use this query: show tables; This is how we can see all tables in ORACLE: SELECT table_name FROM User_tables; This is how we can extract all tables in SQL Server: SELECT * FROM Information_schema.tables; ... Read More

How do I view tables in SQL ?

Updated on 14-Dec-2021 17:07:50
To view tables in SQL, all you need to do is give this command: Show tables; ... Read More

What is Primary Key in SQL ?

Updated on 14-Dec-2021 17:04:38
Primary Key is a constraint in SQL. So, before understanding what exactly is a primary key, let’s understand what exactly is a constraint in SQL. Constraints are the rules enforced on data columns on a table. These are used to limit the type of data that can go into a table. Constraints can either be column level or table level. Let’s look at the different types of constraints which are present in SQL: Constraint Description NOT NULL Ensures that a column cannot have a NUL... Read More

What is SQL server ?

Updated on 14-Dec-2021 16:57:09
To understand what exactly is SQL Server, we need to understand what is DBMS and RDBMS. DBMS stands for Database Management System. When we have a huge database with us, we would need a proper management system which would help us organise this database.  There are 4 types of database management systems: Hierarchical Network Relational Object-Oriented. Out of these database management systems, SQL Server comes under the category of Relational database management system.  A re... Read More