What is the difference between a view and a table?

Vaibhav Kothia May 26, 2023 0 Comments

A view is a virtual table that is created from the result set of a SQL query. It does not contain any data itself, but rather references the underlying tables and columns. For example, a view can be created to show the total number of orders from a certain time period.

A table is a physical representation of data in a database. It contains the actual data that is stored in the database. For example, a table can be created to store customer information, such as name, address, and phone number.

What is the difference between a primary key and a foreign key?

Vaibhav Kothia May 26, 2023 0 Comments

A primary key is a unique identifier for a row in a table. It can be a single column or a combination of columns. For example, a table of students may have a primary key of student_id, which is a unique identifier for each student.

A foreign key is a field in a table that is used to link two tables together. It is a reference to the primary key of another table. For example, a table of students may have a foreign key of class_id, which is a reference to the primary key of the class table.

How do you create a database in Oracle?

Vaibhav Kothia May 26, 2023 0 Comments

In Oracle, you can create a database by using the CREATE DATABASE statement.

For example, the following statement creates a database named “testdb” with the default settings:

CREATE DATABASE testdb;

What are the different types of Oracle Database objects?

Vaibhav Kothia May 26, 2023 0 Comments

1. Tables: A table is a collection of related data stored in a structured format within a database. For example, a customer table might contain the columns customer_id, first_name, last_name, email, and address.

2. Views: A view is a virtual table based on the result set of an SQL statement. For example, a view might contain all customer records from the customer table who have an email address.

3. Indexes: An index is a performance-tuning method of allowing faster retrieval of records. For example, an index on the customer_id column of the customer table would allow faster retrieval of customer records.

4. Sequences: A sequence is an object used to generate unique numbers. For example, a sequence might be used to generate customer_id numbers for new customer records.

5. Stored Procedures: A stored procedure is a set of SQL statements that can be stored in the database and executed as a single unit. For example, a stored procedure might be used to generate a report based on a set of parameters.

6. Triggers: A trigger is a stored procedure that is executed when a certain event occurs. For example, a trigger might be used to update a customer’s address when their record is updated in the customer table.

What is Oracle Database and why is it used?

Vaibhav Kothia May 26, 2023 0 Comments

Oracle Database is an object-relational database management system (ORDBMS) developed by Oracle Corporation. It is used to store and manage data for large applications, web sites, and other distributed applications. Oracle Database is used to store, organize, and retrieve data in a secure and efficient manner. It is also used to create and manage databases for web applications, data warehouses, and other applications. For example, Oracle Database can be used to store customer information, product information, and financial data. It can also be used to create and manage databases for e-commerce websites, data warehouses, and other applications.