MySQL : 열을 개별적으로 계산하는 방법은 무엇입니까?

Question

보통 나는 SQL 쿼리에 대한 자신감이 있지만,이 질문은 저의 머리를 긁적니다. 나는 이것 같이 느낀다 - 빠른 수정이어야한다, 그러나 나는 다만 그것을 보지 않고있다.

하나의 쿼리에서 동일한 테이블의 여러 값에 대해 계산을 수행하려고합니다.

"0000000000000000"이 단지 빈 바이트 배열을 나타내는 것에 신경 쓰지 마십시오.

이러한 검색어를 결합하는 쉬운 방법이 있습니까? 나는이 일을 할 생각

SELECT COUNT(ssn) AS patient_count, 'ssn' AS count_type 
FROM patients 
WHERE ssn="0000000000000000"; 
UNION 
SELECT COUNT(firstname) AS patient_count, 'firstname' AS count_type 
FROM patients 
WHERE firstname="0000000000000000" 
UNION 
SELECT COUNT(lastname) AS patient_count, 'lastname' AS count_type 
FROM patients 
WHERE lastname="0000000000000000" 

Answer 1

UNION과 시도?

SELECT * 
FROM 
(SELECT COUNT(ssn) AS ssn_count 
FROM patients 
WHERE ssn="0000000000000000") AS ssn 
CROSS JOIN 
(SELECT COUNT(firstname) AS firstname_count 
FROM patients 
WHERE firstname="0000000000000000") AS firstname 
CROSS JOIN 
(SELECT COUNT(lastname) AS lastname_count 
FROM patients 
WHERE lastname="0000000000000000") AS lastname 

Answer 2

당신이 뭔가를 할 수

SELECT COUNT(ssn) 
FROM patients 
WHERE ssn="0000000000000000"; 
UNION 
SELECT COUNT(firstname) 
FROM patients 
WHERE firstname="0000000000000000" 
UNION  
SELECT COUNT(lastname) 
FROM patients 
WHERE lastname="0000000000000000" 

Answer 3

SELECT SUM(CASE WHEN ssn = '0000000000000000' THEN 1 ELSE 0 END) AS ssn_count, 
     SUM(CASE WHEN firstname = '0000000000000000' THEN 1 ELSE 0 END) AS first_count, 
     SUM(CASE WHEN lastname = '0000000000000000' THEN 1 ELSE 0 END) AS last_count 
    FROM patients 
    WHERE ssn = '0000000000000000' 
     OR firstname = '0000000000000000' 
     OR lastname = '0000000000000000' 

Answer 4

-

SELECT COUNT(ssn) 
FROM patients 
WHERE ssn="0000000000000000"; 

SELECT COUNT(firstname) 
FROM patients 
WHERE firstname="0000000000000000" 

SELECT COUNT(lastname) 
FROM patients 
WHERE lastname="0000000000000000" 

etc...