如何用空值更新列 [英] How to update column with null value

问题描述

我正在使用mysql，需要用空值更新一列.我已经尝试了许多不同的方法，而我得到的最好的结果是一个空字符串.

I am using mysql and need to update a column with a null value. I have tried this many different ways and the best I have gotten is an empty string.

有特殊的语法可以做到这一点吗?

Is there a special syntax to do this?

推荐答案

无特殊语法:

CREATE TABLE your_table (some_id int, your_column varchar(100));

INSERT INTO your_table VALUES (1, 'Hello');

UPDATE your_table
SET    your_column = NULL
WHERE  some_id = 1;

SELECT * FROM your_table WHERE your_column IS NULL;
+---------+-------------+
| some_id | your_column |
+---------+-------------+
|       1 | NULL        |
+---------+-------------+
1 row in set (0.00 sec)

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