(Queries, Union, Joins, Aggregations)

• 1. Explain different types of joins?
• 2. Tell me about the use case of cross join
• 3. Tell me about the use case of self-join
• 4. What are aggregate functions in SQL?
• 5. How do we use Case statement in SQL? Give example
• 6. Difference and Similarities between General Case Statement and Case Expression in Sql.?
• 7. Find the total number of records in output when you join two tables, assuming that there are duplicate key values.
• 8. What are the rules to follow when you are using UNION operator?
• 9. How we can combine two or more queries result in to one without loosing any data?
• 10. What is the difference and Similarity between union and union all?
• 11. Explain the difference between Join and Union.
• 12. Can we use Aggregate function as Window function?
• 13. What are the usecase of windows function in SQL?
• 14. How can you fetch common records from two tables?
• 15. How can you fetch alternate records from a table?
• 16. Name the operator which can be used in a query for pattern matching?
• 17. How can you fetch the first 5 characters from a string?