[英]Mysql update set all null then set column where id in one query
是否可以先將所有值設置為 null，然后在單個查詢中設置值。
換句話說，可以在單個查詢中做到這一點：
UPDATE table SET column = NULL;
UPDATE table SET column = 'value' WHERE id = 'id';
您可以使用CASE表達式來實現：
UPDATE table
SET column = CASE WHEN id = 'id' THEN 'value' END;
這將僅將id = 'id'的行中的列column更新為值'value' ，所有其他行將設置為null 。
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