CREATE TABLE IF NOT EXISTS seam_log.your_table_name

(

-- 其他字段定义...

disposal_time Nullable(DateTime64(9, 'Asia/Shanghai')) DEFAULT NULL,

-- 其他字段定义...

-- 例如，假设还有一个 ID 字段

id UInt32

)

ENGINE = MergeTree()

ORDER BY id;

INSERT INTO seam_log.your_table_name (id, disposal_time) VALUES (1, NULL);

SELECT * FROM seam_log.your_table_name;

INSERT INTO seam_log.your_table_name (id, disposal_time)

VALUES (3, toDateTime64('2023-04-01 12:34:56.789', 9, 'Asia/Shanghai'));

SELECT * FROM seam_log.your_table_name;

UPDATE seam_log.your_table_name SET disposal_time=toDateTime64('2024-04-01 12:34:56.789', 9, 'Asia/Shanghai') WHERE id =3;

SELECT * FROM seam_log.your_table_name;

UPDATE seam_log.your_table_name SET disposal_time=NULL WHERE id =3;

SELECT * FROM seam_log.your_table_name;

*如果不写Nullable，只写default null .会提示不能不能转换

*Nullable 是需要加的