有没有任何ISO标准的如何在DDL写SQL查询？ [英] Is there any ISO standard of how to write SQL queries in DDL?

问题描述

我正在做我的第一个数据库项目。

I am doing my first database project.

我想知道在DDL中使用以下哪种方式来进行SQL查询。

I would like to know which of the following ways should I use to make SQL queries in DDL.

CREATE TABLE employees (   
    id            INTEGER   PRIMARY KEY,
    first_name    CHAR(50)  NULL,
    last_name     CHAR(75)  NOT NULL,
    dateofbirth   DATE      NULL
);

＃2

#2

CREATE TABLE employees (   
    id INTEGER PRIMARY KEY,
    first_name CHAR(50) NULL,
    last_name CHAR(75) NOT NULL,
    dateofbirth DATE NULL
);

＃3

#3

CREATE TABLE employees (   
    ID            integer   PRIMARY KEY,
    FIRST_NAME    char(50)  NULL,
    LAST_NAME     char(75)  NOT NULL,
    DATAOFBIRTH   data      NULL
);

推荐答案

所以你通常应该去更可读和可维护。有很多不同的约定，我在它们之间切换，根据情况，所有的时间。

It doesn't really matter to the database, and so you should generally go for what's more readable and maintainable. There are a lot of different conventions out there, and I switch between them depending on circumstances all the time. Imo, what's good for a small query isn't the same as what's good for a more-complicated query.

在这种情况下，我认为你的＃3看起来最容易阅读。但这只是我的意见，如果有代码看起来你的方式的惯例或现有的期望，坚持。

In this case, I think your #3 looks most readable. But that's just my opinion and if there are conventions or existing expectations for how the code looks where you are, stick to that.

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