SQL Query For Current business

1. SUM()`SUM()` 함수는 주어진 열의 값을 모두 더한 합계를 반환합니다. SELECT SUM(salary) AS total_salary FROM employees; 이 쿼리는 `employees` 테이블에서 모든 직원의 급여 합계를 반환합니다. 2. AVG()`AVG()` 함수는 주어진 열의 평균값을 계산합니다. SELECT AVG(salary) AS average_salary FROM employees; 이 쿼리는 `employees` 테이블에서 모든 직원의 평균 급여를 반환합니다. 3. COUNT()`COUNT()` 함수는 주어진 조건에 맞는 행의 개수를 반환합니다. SELECT COUNT(*) AS total_employees FROM employees; 이 쿼리는 `employees` ..