如何显示具有空值的行

Question

所以我有这个代码

WITH gaji_kat AS (
SELECT
    *,
    CASE
        WHEN income < 20000 THEN 'Gaji Rendah'
        WHEN income > 50000 then 'Gaji Tinggi'
        ELSE 'Gaji Rata-rata'
    END category
FROM accounts)

SELECT
    category,
    COUNT(category)
FROM gaji_kat
group by 1

结果是这样的

我想显示具有空值的类别。帮助我！

Answer 1

我使用了 COALESCE 函数将空值替换为字符串“Null Category”

WITH gaji_kat AS (
SELECT
    *,
    CASE
        WHEN income < 20000 THEN 'Gaji Rendah'
        WHEN income > 50000 then 'Gaji Tinggi'
        ELSE 'Gaji Rata-rata'
    END category
FROM accounts)

SELECT
    COALESCE(category, 'Null Category') as category,
    COUNT(category)
FROM gaji_kat
group by 1