Schema:
CREATE TABLE "people" (
    "People_ID" int,
    "Age" int,
    "Name" text,
    "Nationality" text,
    "Graduation_College" text,
    PRIMARY KEY ("People_ID")
);
CREATE TABLE "company" (
    "Company_ID" real,
    "Name" text,
    "Headquarters" text,
    "Industry" text,
    "Sales_in_Billion" real,
    "Profits_in_Billion" real,
    "Assets_in_Billion" real,
    "Market_Value_in_Billion" real,
    PRIMARY KEY ("Company_ID")
);
CREATE TABLE "employment" (
    "Company_ID" int,
    "People_ID" int,
    "Year_working" int,
    PRIMARY KEY ("Company_ID","People_ID"),
    FOREIGN KEY ("Company_ID") REFERENCES `company`("Company_ID"),
    FOREIGN KEY ("People_ID") REFERENCES `people`("People_ID")
);

Question: How many companies are headquartered in the US?
SQL:
SELECT count(*) FROM company WHERE Headquarters  =  'USA'

Question: List the names of companies by ascending number of sales.
SQL:
SELECT Name FROM company ORDER BY Sales_in_Billion ASC

Question: What are the headquarters and industries of all companies?
SQL:
SELECT Headquarters ,  Industry FROM company

Question: Show the names of companies in the banking or retailing industry?
SQL:
SELECT Name FROM company WHERE Industry  =  "Banking" OR Industry  =  "Retailing"

Question: What is the maximum and minimum market value of companies?
SQL:
SELECT max(Market_Value_in_Billion) ,  min(Market_Value_in_Billion) FROM company

Question: What is the headquarter of the company with the largest sales?
SQL:
SELECT Headquarters FROM company ORDER BY Sales_in_Billion DESC LIMIT 1

Question: Show the different headquarters and number of companies at each headquarter.
SQL:
SELECT Headquarters ,  COUNT(*) FROM company GROUP BY Headquarters

Question: Show the most common headquarter for companies.
SQL:
SELECT Headquarters FROM company GROUP BY Headquarters ORDER BY COUNT(*) DESC LIMIT 1

Question: Show the headquarters that have at least two companies.
SQL:
SELECT Headquarters FROM company GROUP BY Headquarters HAVING COUNT(*)  >=  2

Question: Show the headquarters that have both companies in banking industry and companies in oil and gas industry.
SQL:
SELECT Headquarters FROM company WHERE Industry  =  "Banking" INTERSECT SELECT Headquarters FROM company WHERE Industry  =  "Oil and gas"

Question: Show the names of companies and of employees.
SQL:
SELECT T3.Name ,  T2.Name FROM employment AS T1 JOIN people AS T2 ON T1.People_ID  =  T2.People_ID JOIN company AS T3 ON T1.Company_ID  =  T3.Company_ID

Question: Show names of companies and that of employees in descending order of number of years working for that employee.
SQL:
SELECT T3.Name ,  T2.Name FROM employment AS T1 JOIN people AS T2 ON T1.People_ID  =  T2.People_ID JOIN company AS T3 ON T1.Company_ID  =  T3.Company_ID ORDER BY T1.Year_working

Question: Show the names of employees that work for companies with sales bigger than 200.
SQL:
SELECT T2.Name FROM employment AS T1 JOIN people AS T2 ON T1.People_ID  =  T2.People_ID JOIN company AS T3 ON T1.Company_ID  =  T3.Company_ID WHERE T3.Sales_in_Billion  >  200

Question: Show the names of companies and the number of employees they have
SQL:
SELECT T3.Name ,  COUNT(*) FROM employment AS T1 JOIN people AS T2 ON T1.People_ID  =  T2.People_ID JOIN company AS T3 ON T1.Company_ID  =  T3.Company_ID GROUP BY T3.Name

Question: List the names of people that are not employed by any company
SQL:
SELECT Name FROM people WHERE People_ID NOT IN (SELECT People_ID FROM employment)

Question: list the names of the companies with more than 200 sales in the descending order of sales and profits.
SQL:
SELECT name FROM company WHERE Sales_in_Billion  >  200 ORDER BY Sales_in_Billion ,  Profits_in_Billion DESC