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判斷時間戳記為空 PostgreSQL: Select where timestamp is empty

使用 IS NULL 或 IS NOT NULL

--

null in SQL means 'unknown'.

This means that the result of using any comparison operator, like =, with a null is also 'unknown'.

To check if a column is NULL (or not NULL), use the special syntax of IS NULL (or IS NOT NULL) instead of using =.

Applying that to your statement,

SELECT * FROM table WHERE timestamp IS NULL;

should work.

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轉自 https://stackoverflow.com/questions/4476172/postgresql-select-where-timestamp-is-empty

 

 

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