Walmart Labs Data Engineer Interview Questions and Answers

To get the second to last element from a SQL table, use the OFFSET-FETCH clause.

• Use the ORDER BY clause to sort the table in descending order.

• Use the OFFSET-FETCH clause to skip the last row and fetch the second to last row.

• Example: SELECT column_name FROM table_name ORDER BY column_name DESC OFFSET 1 ROWS FETCH NEXT 1 ROWS ONLY;

Triggers are database objects that automatically execute in response to certain events or changes in data.

• Triggers are used to enforce business rules or data integrity.

• They can be used to audit changes to data.

• Triggers can be set to execute before or after an event, such as an insert, update, or delete operation.

• They can be defined on tables, views, or schemas.

• Examples of triggers include sending an email notification ...read more