What does groupby mean in sql

GROUP BY is a statement in SQL used to group and aggregate data. It groups rows by grouping key and then applies aggregate functions such as calculating sum, count, or average.

The meaning of GROUP BY in SQL

GROUP BY is a statement in SQL that is used to convert data Centralized rows group and aggregate data within the same group.

How it works

The GROUP BY statement accepts one or more grouping keys as parameters. The keys are the columns in the dataset that determine which rows are grouped together.

After grouping, SQL will execute an aggregate function for each group, for example:

• SUM: Calculate the sum of a column in the group
• COUNT: Calculate the rows in the group Number of
• AVG: Calculate the average value of a column in a group
• MIN: Find the minimum value of a column in a group
• MAX: Find the maximum value of a column in a group

Syntax

The syntax of the GROUP BY statement is as follows:

<code>SELECT <聚合函数>(<列名>)
FROM <表名>
GROUP BY <分组键></code>

Example

The following Example to calculate the sum of sales for each product category:

<code>SELECT SUM(Sales)
FROM Sales
GROUP BY ProductCategory</code>

This query will return a new data set containing each product category and its corresponding sales sum.

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