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문제Column NameTypeidintsalaryint[Table : Employee]id is the primary key (column with unique values) for this table.Each row of this table contains information about the salary of an employee. Write a solution to find the second highest distinct salary from the Employee table. If there is no second highest salary, return null 주어진 Employee 테이블에서 두 번째로 높은 급여를 조회해라. 두 번째 급여가 없다면 null을 조회해라. 풀이SELECT..

문제Column NameTypeidintnamevarchar[Table : Customers]id is the primary key (column with unique values) for this table.Each row of this table indicates the ID and name of a customer. Column NameTypeidintcustomerIdint[Table : Orders]id is the primary key (column with unique values) for this table.customerId is a foreign key (reference columns) of the ID from the Customers table.Each row of this ta..

문제Column NameTypeidintemailvarchar[Table : Person]id is the primary key (column with unique values) for this table.Each row of this table contains an email. The emails will not contain uppercase letters. Write a solution to report all the duplicate emails. Note that it's guaranteed that the email field is not NULL.주어진 테이블에서 중복된 이메일을 출력해라. 풀이SELECT DISTINCT(ABC.email)FROM (SELECT email, COUNT..

문제Column NameTypepersonIdintlastNamevarcharfirstNamevarchar[Table : Person]personId is the primary key (column with unique values) for this table.This table contains information about the ID of some persons and their first and last names. Column NameTypeaddressIdintpersonIdintcityvarcharstatevarchar[Table : Address]addressId is the primary key (column with unique values) for this table.Each row..