Chetu Web Developer Interview Questions and Answers

ACID properties in DBMS ensure data integrity and consistency in transactions.

• ACID stands for Atomicity, Consistency, Isolation, Durability.

• Atomicity ensures that either all operations in a transaction are completed successfully or none are.

• Consistency ensures that the database remains in a valid state before and after the transaction.

• Isolation ensures that multiple transactions can run concurrently without affecting each other.

• Durability ensures that once a transaction is co...read more

HTTP is a protocol used for transferring data over the internet.

• HTTP stands for Hypertext Transfer Protocol.

• It is a request-response protocol where a client sends a request to a server and the server responds with the requested data.

• HTTP uses methods like GET, POST, PUT, DELETE to specify the action to be performed.

• Headers are used to provide additional information about the request or response.

• Status codes like 200 (OK), 404 (Not Found) are used to indicate the outcome of th...read more

Different types of joins in SQL include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN: Returns rows when there is a match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

Session state in HTTP refers to the data stored on the server about a user's interactions during a session.

• Session state allows the server to remember information about a user's interactions during a session.

• It is typically stored in server-side memory or a database.

• Session state is used to maintain user authentication, shopping cart contents, and other user-specific data.

• Cookies are often used to maintain session state by storing a session ID on the client side.

Constraints in SQL are rules that are enforced on data columns in a table.

• Constraints ensure data integrity by enforcing rules on data columns

• Common constraints include NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK

• Example: NOT NULL constraint ensures a column cannot have a NULL value

Triggers in SQL are special stored procedures that are automatically executed when certain events occur in a database.

• Triggers can be used to enforce business rules, maintain referential integrity, and automate tasks.

• There are two main types of triggers: Before Triggers and After Triggers.

• Example: A trigger can be set to automatically update a 'last_modified' column whenever a row is updated in a table.

To create a Python session, you can use the 'requests' library to make HTTP requests and maintain session state.

• Import the 'requests' library

• Create a session object using 'requests.Session()'

• Use the session object to make HTTP requests, which will automatically handle cookies and other session data