使用DATE字段作为MySQL的日期维度的主键

问题描述

我想在MySQL数据仓库中处理日期维度。 （我在DW世界的新手）

我用google做了一些搜索，看到很多表结构（大部分）日期维度，主键是一个简单的 UNSIGNED INTEGER 。

为什么不使用 DATE 字段作为主键，因为MySQL是3字节VS 4字节 INTEGER ？

Ex：

  CREATE TABLE dimDate 
 id INTEGER UNSIGNED NOT NULL PRIMARY AUTOI_NCREMENT，
日期DATE NOT NULL，
 dayOfWeek 
 ... 
  

VS

  CREATE TABLE dimDate 
日期DATE NOT NULL PRIMARY，
 dayOfWeek 
 ... 
  pre> 
 
解决方案
如果您有一个列为日期的表类型，哪里没有两行将有相同的日期，那么您可以肯定地将此列用作 PRIMARY KEY 。
 
 
 
你看到很多例子，主键是简单的 UNSIGNED INTEGER ，因为有许多情况下，主键没有完美的候选人。  AUTO_INCREMENT 允许此列在插入期间由数据库自动填充（并且是唯一的）。
 
I want to handle a date dimension in a MySQL datawarehouse. (I m a  newbie in the DW world)

I made some searches with google and saw a lot of table structures (most of) date dimension where the Primary Key is a simple UNSIGNED INTEGER.

Why don't use a DATE field as primary key since with MySQL it is 3 Bytes VS 4 Bytes for INTEGER?

Ex:
CREATE TABLE dimDate
id INTEGER UNSIGNED NOT NULL PRIMARY AUTOI_NCREMENT,
date DATE NOT NULL,
dayOfWeek
...
VS
CREATE TABLE dimDate
date DATE NOT NULL PRIMARY,
dayOfWeek
...
 解决方案 
If you have a table with a column that is of date type and where no two rows will ever have the same date, then you can surely use this column as PRIMARY KEY.
You see a lot of examples where the Primary Key is a simple UNSIGNED INTEGER because there are many cases where there is no perfect candidate for Primary Key. The AUTO_INCREMENT allows this column to be automatically filled by the database (and be unique) during inserts .
                        
这篇关于使用DATE字段作为MySQL的日期维度的主键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！