创建日期类型的表并在 MySQL 上使用其默认值作为 CURRENT_DATE [英] CREATE table of date type and use its default value as CURRENT_DATE on MySQL

问题描述

我尝试在 sql 命令中运行下面的代码，但是代码行 start_date date DEFAULT CURRENT_DATE 有问题，不知道为什么.我只需要约会.

I tried running below code in sql command, but the code line start_date date DEFAULT CURRENT_DATE had issues, got no idea why. I needed only date.

但是如果我用 start_date datetime DEFAULT CURRENT_TIMESTAMP 替换它SQL 将运行，但我的想法是我只需要存储日期而不是日期时间.

But if I replace that with start_date datetime DEFAULT CURRENT_TIMESTAMP the SQL will run but the idea is I only need to store date and not datetime.

如何在不使用时间戳且后者仅转换为日期的情况下执行此操作?

How do I do it without using timestamp and latter converting to only date?

CREATE TABLE advertisement (
    id int not null AUTO_INCREMENT,
    PRIMARY KEY(id),
    summary text DEFAULT null,
    featured_image varchar(50) DEFAULT null, 
    start_date date DEFAULT CURRENT_DATE,
    end_date date not null,
    link text DEFAULT null,
    added_date datetime DEFAULT CURRENT_TIMESTAMP,
    updated_date datetime ON UPDATE CURRENT_TIMESTAMP
)

推荐答案

文档 很清楚这适用于 datetime 列，但不适用于 date 列:

The documentation is quite clear that this works for datetime columns but not date columns:

这意味着，例如，您不能为日期设置默认值列作为函数的值，例如 NOW() 或 CURRENT_DATE.例外是您可以指定 CURRENT_TIMESTAMP 作为默认值用于 TIMESTAMP 和 DATETIME 列.

This means, for example, that you cannot set the default for a date column to be the value of a function such as NOW() or CURRENT_DATE. The exception is that you can specify CURRENT_TIMESTAMP as the default for TIMESTAMP and DATETIME columns.

如果您真的一心想忽略时间组件，则必须使用触发器来设置该值，而不是使用 default 约束.

If you really have your heart set on ignoring the time component, you will have to use a trigger to set the value, rather than a default constraint.

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