Q2
Aggregation & GROUP BY
45 stations · 6.4hCOUNT, SUM, AVG with GROUP BY and HAVING, ratios and percentages. 45 interview problems explained by Everyday Data Science (6.4h of video), grouped into 3 patterns such as Ratios & percentages, Filter groups with HAVING, Count & sum per group.
Start this line →- Ratios & percentages10
- Filter groups with HAVING8
- Count & sum per group12
- Other19
Ratios & percentages
0 of 10 passed- Queries Quality and PercentageLC 1211 · 13:28EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
- Average Selling PriceLC 1251 · 17:11EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
- Percentage of Users Attended a ContestLC 1633 · 5:55EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
- Confirmation RateLC 1934 · 11:47MediumGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
- Orders With Maximum Quantity Above AverageLC 1867 · 7:26 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
- Average Salary: Departments VS CompanyLC 615 · 14:48 · LeetCode PremiumHardLeetCode ↗ (opens in a new tab)
- Get Highest Answer Rate QuestionLC 578 · 9:18 · LeetCode PremiumMediumMetaLeetCode ↗ (opens in a new tab)
- Friend Requests I: Overall Acceptance RateLC 597 · 11:21 · LeetCode PremiumEasyMetaLeetCode ↗ (opens in a new tab)
Filter groups with HAVING
0 of 8 passed- Customer Placing the Largest Number of OrdersLC 586 · 9:02EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
- Classes With at Least 5 StudentsLC 596 · 4:06EasyGoogle · Microsoft · +1 more companiesLeetCode ↗ (opens in a new tab)
- Actors and Directors Who Cooperated At Least Three TimesLC 1050 · 5:36EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
- Orders With Maximum Quantity Above AverageLC 1867 · 7:26 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
Count & sum per group
0 of 12 passed- Customer Placing the Largest Number of OrdersLC 586 · 9:02EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
- Number of Comments per PostLC 1241 · 15:09 · LeetCode PremiumEasyMetaLeetCode ↗ (opens in a new tab)
- Daily Leads and PartnersLC 1693 · 4:56EasyGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
- Find Total Time Spent by Each EmployeeLC 1741 · 6:56EasyAmazon · CognizantLeetCode ↗ (opens in a new tab)
- The Number of Rich CustomersLC 2082 · 3:54 · LeetCode PremiumEasyathenahealthLeetCode ↗ (opens in a new tab)
- Primary Department for Each EmployeeLC 1789 · 10:47EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
- Find Followers CountLC 1729 · 3:54EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
- Number of Unique Subjects Taught by Each TeacherLC 2356 · 3:12EasyGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
Other
0 of 19 passed- Game Play Analysis ILC 511 · 3:38EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
- Project Employees ILC 1075 · 4:31EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
- Sales Analysis IIILC 1084 · 8:15EasyGoogle · Amazon · +1 more companiesLeetCode ↗ (opens in a new tab)
- Find Candidates for Data Scientist PositionLC 3051 · 4:06 · LeetCode PremiumEasyHashedInLeetCode ↗ (opens in a new tab)
- Find Candidates for Data Scientist Position IILC 3278 · 13:26 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
- Customer Purchasing Behavior AnalysisLC 3230 · 18:34 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
All 45 stations in order
- 1.Duplicate Emails (LeetCode 182)
- 2.Customer Placing the Largest Number of Orders (LeetCode 586)
- 3.Classes With at Least 5 Students (LeetCode 596)
- 4.Actors and Directors Who Cooperated At Least Three Times (LeetCode 1050)
- 5.Reported Posts (LeetCode 1113)
- 6.Queries Quality and Percentage (LeetCode 1211)
- 7.Number of Comments per Post (LeetCode 1241)
- 8.Average Selling Price (LeetCode 1251)
- 9.Bank Account Summary II (LeetCode 1587)
- 10.Daily Leads and Partners (LeetCode 1693)
- 11.Find Total Time Spent by Each Employee (LeetCode 1741)
- 12.The Number of Rich Customers (LeetCode 2082)
- 13.Product Sales Analysis II (LeetCode 1069)
- 14.Game Play Analysis I (LeetCode 511)
- 15.Primary Department for Each Employee (LeetCode 1789)
- 16.Find Followers Count (LeetCode 1729)
- 17.Percentage of Users Attended a Contest (LeetCode 1633)
- 18.Confirmation Rate (LeetCode 1934)
- 19.Orders With Maximum Quantity Above Average (LeetCode 1867)
- 20.Project Employees I (LeetCode 1075)
- 21.League Statistics (LeetCode 1841)
- 22.Average Salary: Departments VS Company (LeetCode 615)
- 23.Sales Analysis III (LeetCode 1084)
- 24.Number of Unique Subjects Taught by Each Teacher (LeetCode 2356)
- 25.Product Sales Analysis V (LeetCode 2329)
- 26.Get Highest Answer Rate Question (LeetCode 578)
- 27.Friend Requests I: Overall Acceptance Rate (LeetCode 597)
- 28.Bank Account Summary (LeetCode 1555)
- 29.Article Views II (LeetCode 1149)
- 30.Find Candidates for Data Scientist Position (LeetCode 3051)
- 31.Loan Types (LeetCode 2990)
- 32.Calculate Compressed Mean (LeetCode 2985)
- 33.Highest Salaries Difference (LeetCode 2853)
- 34.Bikes Last Time Used (LeetCode 2687)
- 35.Find Latest Salaries (LeetCode 2668)
- 36.Reported Posts II (LeetCode 1132)
- 37.Count Occurrences in Text (LeetCode 2738)
- 38.Find Candidates for Data Scientist Position II (LeetCode 3278)
- 39.Find Top Scoring Students (LeetCode 3182)
- 40.Find Top Scoring Students II (LeetCode 3188)
- 41.Customer Purchasing Behavior Analysis (LeetCode 3230)
- 42.Analyze Subscription Conversion (LeetCode 3497)
- 43.Find Books with Polarized Opinions (LeetCode 3642)
- 44.Find Stores with Inventory Imbalance (LeetCode 3626)
- 45.Find Users with High Token Usage (LeetCode 3793)