汇总数据

SQL 中级

Jasmin Ludolf

Data Science Content Developer, DataCamp

一叠文件和放大镜的照片

聚合函数

AVG(), SUM(), MIN(), MAX(), COUNT()

SELECT AVG(budget)
FROM films;

|avg             |
|----------------|
|39902826.2684...|

SELECT SUM(budget)
FROM films;

|sum         |
|------------|
|181079025606|

SELECT MIN(budget)
FROM films;

|min|
|---|
|218|

SELECT MAX(budget)
FROM films;

|max        |
|-----------|
|12215500000|

仅限数值字段

多种数据类型

MIN() <-> MAX()

最小值 <-> 最大值

最低 <-> 最高

A <-> Z

1715 <-> 2022

0 <-> 100

SELECT MIN(country)
FROM films;

|min        |
|-----------|
|Afghanistan|

SELECT MAX(country)
FROM films;

|max         |
|------------|
|West Germany|

SELECT MIN(country)
FROM films;

|min        |
|-----------|
|Afghanistan|

SELECT MIN(country) AS min_country
FROM films;

|min_country|
|-----------|
|Afghanistan|

SQL 中级