mysql - MySQL can distinguish NULL and ""(null character string)

Question

I set default value in a field NOT NULL. The sql is as follows.

insert into table_name () values ()

I expected this sql should be rejected by MySQL as a field restricts NULL. But, the field had a value ""(null character string).

Then, I tried another sql.

insert into table_name (name) values (NULL)

As this sql was rejected, no value was inserted.

MySQL seems to distinguish NULL and "". Do I have to avoid first sql such as "values ()"?

score 1 · Accepted Answer

一个好的做法是始终使列不为空，并在创建表时设置默认值。

在插入时，如果您不提供值，则将为该列分配默认值。

score 0 · Accepted Answer

我是否必须在设置为 NOT NULL 的字段中设置默认值？

是，如果您正在执行INSERTwhere in 您将不会为 NOT NULL 列设置任何值

和

NO不再需要，如果您在上为 NOT NULL 的列提供值INSERT。

你可以参考这个

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