题解 | 牛客直播转换率

SELECT
    c.course_id,
    c.course_name,
    COALESCE(
        ROUND(SUM(CASE WHEN b.if_sign = '1' THEN 1 ELSE 0 END) / SUM(CASE WHEN b.if_vw = '1' THEN 1 ELSE 0 END) * 100,2)
        ) AS "sign_rate(%)"
FROM behavior_tb AS b
INNER JOIN course_tb AS c
    ON (b.course_id = c.course_id)
GROUP BY c.course_id,c.course_name
ORDER BY c.course_id;