From 7b32d3b6cb52fafbdf3115c0c1d48cc9c92cb2ef Mon Sep 17 00:00:00 2001 From: Tanmay Date: Thu, 6 Oct 2022 14:59:19 +0100 Subject: [PATCH] Adds questions. --- database/notes/09-subqueries-views.md | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/database/notes/09-subqueries-views.md b/database/notes/09-subqueries-views.md index 575c55d..fec4283 100644 --- a/database/notes/09-subqueries-views.md +++ b/database/notes/09-subqueries-views.md @@ -13,6 +13,7 @@ - [Index Range scan](#index-range-scan) - [Index seek](#index-seek) - [Some guidelines for optimizing MySQL queries](#some-guidelines-for-optimizing-mysql-queries) + - [Practice questions](#practice-questions) ## Sub-queries @@ -223,4 +224,12 @@ This happens when you specify a condition in WHERE clause like searching an empl * Avoid unnecessary columns in SELECT clause Instead of using ‘SELECT *’, always specify columns in the SELECT clause to improve MySQL performance. Because unnecessary columns cause additional load on the database, slowing down its performance as well whole systematic process. * Pagination -* Avoid SELECT DISTINCT \ No newline at end of file +* Avoid SELECT DISTINCT + +## Practice questions +* [Sub-queries - I](https://leetcode.com/problems/customers-who-never-order/) +* [Sub-queries - II](https://leetcode.com/problems/sales-person/) +* [Sub-queries - III](https://leetcode.com/problems/consecutive-available-seats/) +* [Sub-queries - IV](https://leetcode.com/problems/sales-analysis-ii/) +* [Sub-queries - V](https://leetcode.com/problems/students-with-invalid-departments/) +* [Sub-queries - VI](https://leetcode.com/problems/customer-who-visited-but-did-not-make-any-transactions/) \ No newline at end of file