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freeCodeCamp/guide/chinese/sql/sql-avg-function/index.md
2018-10-16 21:32:40 +05:30

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---
title: SQL Avg Function
localeTitle: SQL平均功能
---
## SQL平均AVG功能
“Average”是AggregateGroup By函数。它用于计算SQL语句返回的行集中的数字列的平均值。
以下是使用该函数的语法:
```sql
select groupingField, avg(num_field)
from table1
group by groupingField
```
以下是使用学生表的示例:
```sql
select studentID, FullName, avg(sat_score)
from student
group by studentID, FullName;
```
![图像-1](https://github.com/SteveChevalier/guide-images/blob/master/avg_function01.JPG?raw=true)