SQL 自定义顺序按子句 [英] SQL Custom Order By Clause

问题描述

一个简单的问题.我有一个查询带回 2 列描述"和金额"在描述中，我们有 3 个结果.

A quick Question. I have a query that brings back 2 columns 'Description' and 'Amount' In the Description we have 3 outcomes.

'黄金 - 拥有'、'青铜 - 无地'和'白银 - 确定/提供'

'Gold - owned', 'Bronze - no land' and 'Silver - identified / offered'

我希望结果按以下顺序显示金、银、铜

I would like the result to show in an order of Gold,Silver,Bronze

Order By Asc 或 Desc 不能实现这一点.有没有办法自定义 Order by 子句?

Order By Asc or Desc does not achieve this. Is there a way to customize a Order by clause?

对此有任何帮助将不胜感激，谢谢生锈了

Any Help on this Would be appreciated thanks Rusty

推荐答案

在 CASE 内部，您可以为每个分配一个数值并按升序排列.如果您需要查询大表，请考虑在 Description 上添加索引以提高排序性能.

Inside of a CASE, you may ascribe a numeric value to each and order those ascending. If you will need to query a large table, consider adding an index on Description to improve sorting performance.

ORDER BY
  CASE 
    WHEN Description = 'Gold - owned' THEN 0
    WHEN Description = 'Silver - identified / offered' THEN 1
    WHEN Description = 'Bronze - no land' THEN 2
    ELSE 99 /* Any other value (which you should not have) sorts after all */
  END ASC  /* And don't forget to be explicit about ASC order though it's the default */

由于这与 ORDER BY 中的普通列一样工作，如果您需要按 Amount 或其他列排序，可以附加逗号.

Since this works like a normal column in the ORDER BY, if you needed to then sort by the Amount or other column, it can be appended with a comma.

ORDER BY 
  CASE
    WHEN Description = 'Gold '...
  END ASC,
  Amount DESC,
  AnotherColumn ASC

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