[programmers] 문제 풀이 04

| 조건에 맞는 회원수 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/131535

SELECT COUNT(USER_ID) USERS
  FROM USER_INFO
 WHERE JOINED LIKE '2021%'
   AND AGE BETWEEN 20 AND 29;

| 두 수의 합

https://school.programmers.co.kr/learn/courses/30/lessons/120802

class Solution {
    public int solution(int num1, int num2) {
        int answer = num1 + num2;
        return answer;
    }
}

| 조건에 맞는 아이템들의 가격의 총합 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/273709

SELECT SUM(PRICE) TOTAL_PRICE
  FROM ITEM_INFO
 WHERE RARITY = 'LEGEND';

| 진료과별 총 예약 횟수 출력하기

https://school.programmers.co.kr/learn/courses/30/lessons/132202

SELECT MCDP_CD AS '진료과코드',
       COUNT(*) AS '5월예약건수'
  FROM APPOINTMENT
 WHERE DATE_FORMAT(APNT_YMD, '%Y-%m') = '2022-05'
 GROUP BY MCDP_CD
 ORDER BY 2, 1;

| 숫자 비교하기

https://school.programmers.co.kr/learn/courses/30/lessons/120807

class Solution {
    public int solution(int num1, int num2) {
        int answer = 0;
        
        if(num1 == num2){
            answer = 1;
        }else{
            answer = -1;
        } 
        
        return answer;
    }
}

| 배열의 평균값

https://school.programmers.co.kr/learn/courses/30/lessons/120817

class Solution {
    public double solution(int[] numbers) {
        double answer = 0;
        double addNum = 0;
        
        for(int i=0; i<numbers.length; i++){
            addNum += numbers[i];
        }
        
        answer = addNum / numbers.length;
       
        return answer;
    }
}

| 문자열 붙여서 출력하기

https://school.programmers.co.kr/learn/courses/30/lessons/181946

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        
        System.out.println(a+b);
    }
}

| 고양이와 개는 몇 마리 있을까

https://school.programmers.co.kr/learn/courses/30/lessons/59040

SELECT ANIMAL_TYPE,
       COUNT(*) COUNT
  FROM ANIMAL_INS
 GROUP BY ANIMAL_TYPE
 ORDER BY ANIMAL_TYPE

| 중성화 여부 파악하기

https://school.programmers.co.kr/learn/courses/30/lessons/59409

SELECT ANIMAL_ID,
       NAME,
       CASE 
        WHEN SEX_UPON_INTAKE LIKE '%Neutered%' THEN 'O'
        WHEN SEX_UPON_INTAKE LIKE '%Spayed%' THEN 'O'
        ELSE 'X'
       END AS 중성화
  FROM ANIMAL_INS
 ORDER BY ANIMAL_ID;
 
 SELECT ANIMAL_ID, NAME,
    CASE 
        WHEN (SEX_UPON_INTAKE REGEXP ('Neutered|Spayed')) 
        THEN 'O' ELSE 'X' END
        AS 중성화
   FROM ANIMAL_INS;

| 입양 시각 구하기(1)

https://school.programmers.co.kr/learn/courses/30/lessons/59412

SELECT DATE_FORMAT(DATETIME, '%H') AS HOUR,
       COUNT(*) AS COUNT
  FROM ANIMAL_OUTS
 WHERE TIME(DATETIME) BETWEEN '09:00' AND '19:59'
 GROUP BY HOUR
 ORDER BY HOUR;
 
SELECT HOUR(DATETIME) as HOUR, COUNT(*) as COUNT
  FROM ANIMAL_OUTS
 WHERE HOUR(DATETIME) BETWEEN 9 and 19
 GROUP BY HOUR
 ORDER BY HOUR;