Basic SQL questions. Describe a join to a non-technical person. How do you handle a query that does not perform quickly? They want to know that you can use 'explain plans', which I currently do not use (I'm still entry level). Select all customers who purchased at least two items on two separate days. Given a table with a combination of flight paths, how would you identify unique flights if you don't care which city is the destination or arrival location.
probability of the product coming from location A is 0.8 and from location B is 0.6. What is the probability the customers will receive the product from location A or location B SQL - tested on different join , lead , lag, pivoting in sql , sub query, group by having, where, aggregate and think about how you would find outliers)
Derive customer's account status as of month end for all the months in 2019. If for given month, there are more than one rows, pick the data from the latest date within the month. If for given month, there is no data, pick the data from latest date prior to the month You can use last_day function to get month ending date(Eg: last_day(01/01/2015) = 01/31/2015) customer_id event_date status credit_limit 1 1/1/2019 C 1000 1 1/5/2019 F 1000 1 3/10/2019 1000 1 3/10/2019 1000 1 8/27/2019 L 1000 2 1/1/2019 L 2000 2 1/5/2019 2500 2 3/10/2019 2500 3 1/1/2019 S 5000 3 1/5/2019 6000 3 3/10/2019 B 5000 4 3/10/2019 B 10000
SQL question - Table1 year| month| order_id| seller_id| book| quantity| prices 2008|June| 1|888|HP| 2| 2000 2008|June| 1|888|LoTR| 1| 1000 2009|July| 2|999|HP| 1| 1000 Q1. find avg quantity of books solder for every order_id every year? Q2. find max units of books sold for every order_id
Schemas - Sales (sales_id, date , customer_id, Product_id, purchase_amount): Product (P_id, P_Name, Brand_id,B_name) Top 10 products in year XXXX Top 10 products in each year List of customers whose total purchase increased from XXXX-XXXX but decreased from XXXX-XXXX. List of customers who bought both brands "X" & "Y" and at-least 2 products in each brand.
Q1) Find the number of unique days each employee worked Emp Id Task Id Start date End date 1 1 Monday Wednesday 1 2 Monday Tuesday 1 3 Friday Friday 2 1 Monday Friday 2 1 Tuesday Wednesday Hint: Calendar day table or date dimension table Calendar_day Calendar_day_of_week Calendar_year Calendar_month 1900/01/01 Wednesday (3) 1990 1 Q2) How many customers placed orders every month? Table 1: Customer Date customer_id order_id units country 2019/07/01 A 112 5 US 2019/07/02 A 211 4 US 2019/08/02 B 511 4 EU 2019/09/01 C 322 1 JP 2019/09/01 C 322 2 JP 2019/08/05 A 378 6 US 2019/09/10 A 456 7 US
(ordr_date, cust_id, product_id, prc_per_unit, unit) ('2020-10-01', '1', 'AA', 10.5, 2), ('2020-11-01', '1', 'BB', 1.5, 3), ('2020-01-01', '1', 'CC', 3.5, 8), ('2020-01-01', '2', 'CC', 4.5, 3), ('2020-01-01', '2', 'BB', 1.5, 3); 1. List the top 20 customers who have the highest spending 2. Find the highest spent product for each customer
From SQL: 1. If there are 2 tables with m and n rows respectively, then what will be the minimum and maximum number of rows in all the joins. 2. Get the 3rd highest employee salary from employee salary table. 3. Given a product table, the new record gets appended in table with the new timestamp for the product ID. Find out the latest row for that particular product with or without analytical functions. 4. Given there are 2 tables of employee details and employee project details, which all employee are not yet assigned a project. For python: 1. Given a product data frame, the new record gets appended in table with the new timestamp for the product ID. Find out the latest data frame for that particular product with pandas.
Some sql questions. Tell me a time when you did something without getting your manager's approval. What will you do differently?
employee(employee_id,manager_id,join_date) find all the employees who joined before their manager
Viewing 1 - 10 interview questions