SELECT (res.phone_number_count + res.computer_count) AS user_count FROM (
SELECT COUNT(DISTINCT phone_number_id) AS phone_number_count, COUNT(DISTINCT computer_id) AS computer_count
FROM opinions
WHERE case_id = 1
) AS res;
我正在尝试计算唯一的phone_number_ids和computer_ids。
答案 0 :(得分:3)
怎么样:
SELECT COUNT(DISTINCT phone_number_id) + COUNT(DISTINCT computer_id) AS user_count
FROM opinions
WHERE case_id = 1