演员日期超过 null Id's, SQL

Question

我有以下查询

SELECT 
    originaltimestamp, 
    userid,
    YEAR(CAST(SUBSTR(originaltimestamp, 1, 10) AS date)) AS year,
    MONTH(CAST(SUBSTR(originaltimestamp, 1, 10) AS date)) AS month,
    ROW_NUMBER() OVER (PARTITION BY userid ORDER BY originaltimestamp DESC) AS RN
FROM 
    table1
WHERE 
    userid IS NOT NULL 
    AND CAST(SUBSTR(originaltimestamp, 1, 10) AS date) BETWEEN date '2018-01-01' AND date '2021-12-31'
GROUP BY 
    1, 2, 3, 4

但是现在如果我尝试计算所有 ID（不是 null 和 null），我会得到以下信息

SELECT 
    originaltimestamp, 
    userid,
    YEAR(CAST(SUBSTR(originaltimestamp, 1, 10) AS date)) AS year,
    MONTH(CAST(SUBSTR(originaltimestamp, 1, 10) AS date)) AS month,
    ROW_NUMBER() OVER (PARTITION BY userid ORDER BY originaltimestamp DESC) AS RN
FROM 
    table1
WHERE 
    CAST(SUBSTR(originaltimestamp, 1, 10) AS date) BETWEEN date '2018-01-01' AND date '2021-12-31'
GROUP BY 
    1, 2, 3, 4

我收到以下错误

INVALID_CAST_ARGUMENT：值不能转换为日期：

为什么当我排除条件时它不起作用

WHERE userid IS NOT NULL

我如何计算 null id？