SQL查询需求：获取数据表两列各自的最大值

Hey there! Let's figure out how to get the maximum values from Column1 and Column2 in your table.

First, let's align on your data and requirements clearly:

Your Table Data #

Column1 | Column2
--------+--------
1 | 1
3 | 2
1 | 3
2 | 1
2 | 4

You want to retrieve the highest value from Column1 and the highest value from Column2 separately, right?

The SQL Query You Need #

This is straightforward with SQL's MAX() aggregate function. Just run this query (replace your_table_name with the actual name of your table):

SELECT MAX(Column1) AS Max_Column1, MAX(Column2) AS Max_Column2
FROM your_table_name;

Quick Breakdown of the Query #

• MAX(Column1) scans all entries in Column1 and returns the largest value (which is 3 in your sample data)
• MAX(Column2) does the exact same for Column2 (and for your data, that's 4—quick heads up, your example result mentioned "3 : 2" but that looks like a typo, since Column2 has a 4 in the last row!)
• The AS keywords assign friendly names to the result columns, so you can easily tell which max corresponds to which original column

Expected Result #

When you run this query against your sample data, the output will look like this:

Max_Column1 | Max_Column2
------------+------------
3 | 4

That's all there is to it—this query efficiently grabs both max values in a single pass over your table.

内容的提问来源于stack exchange，提问作者Sami Meskaoui