SQL-如何查找列中的最高编号? [英] SQL - How to find the highest number in a column?

问题描述

假设我在客户"表中有以下数据:(仅此而已)

Let's say I have the following data in the Customers table: (nothing more)

ID   FirstName   LastName
-------------------------------
20   John        Mackenzie
21   Ted         Green
22   Marcy       Nate

什么样的SELECT语句可以在ID列中获得22号?

What sort of SELECT statement can get me the number 22, in the ID column?

我需要执行类似的操作来生成唯一的ID.当然，我可以让系统通过自动递增来执行此操作，但是那我将如何获取自动生成的ID?

I need to do something like this to generate a unique ID. Sure I can let the system do this via auto-increment, but then how would I get the auto generated ID?

我想到了SELECT ID FROM Customers并计算返回的行，但这似乎效率很低，在这种情况下，尽管我需要唯一的ID 23，但它会错误地返回"3".

I thought of SELECT ID FROM Customers and counting the rows returned but this seems horribly inefficient, and in this case, it will incorrectly return "3", though I need a unique ID of 23.

推荐答案

您可以

SELECT MAX(ID) FROM Customers;

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