使用以下查询在 hive 中处理除以零错误

Question

I have the following statements in hive:

SELECT
    cardno,
    COALESCE(SUM(CASE WHEN shopcode IN (1191,1228,1225,1521) THEN amount_gbp END), 0) / COALESCE(COUNT(DISTINCT CASE WHEN shopcode IN (1191,1228,1225,1521) THEN amount_gbp END), 0) AS active_cards,
    SUM(col1 + col2 + col3 + col4) / COUNT(*)
FROM
    sales
GROUP BY 
    cardno

I get a "division by zero" error, I cannot use nullif in hive so how can I amend the above to account for this error?

Answer 1

First, more recent versions of Hive do support NULLIF() :

. . . / NULLIF(COUNT(DISTINCT CASE WHEN shopcode  in (1191,1228,1225,1521) THEN amount_gbp END), 0)

If not, you can use a CASE expression:

. . . / (CASE WHEN COUNT(DISTINCT CASE WHEN shopcode  in (1191,1228,1225,1521) THEN amount_gbp END) > 0 THEN COUNT(DISTINCT CASE WHEN shopcode  in (1191,1228,1225,1521) THEN amount_gbp END) END)