为此，您可以使用AVG()。以下是语法-select avg(yourColumnName1) as anyAliasName1,
avg(yourColumnName2) as anyAliasName2,
avg(yourColumnName3) as anyAliasName3,
.
.
N
from yourTableName;
让我们创建一个表-mysql> create table demo31
> (
> value1 int,
> value2 int,
> value3 int
> );
借助insert命令将一些记录插入表中-mysql> insert into demo31 values(34,55,67);
mysql> insert into demo31 values(50,60,70);
mysql> insert into demo31 values(100,200,300);
mysql> insert into demo31 values(10,300,200);
使用select语句显示表中的记录-mysql> select *from demo31;
这将产生以下输出-+--------+--------+--------+
| value1 | value2 | value3 |
+--------+--------+--------+
| 34 | 55 | 67 |
| 50 | 60 | 70 |
| 100 | 200 | 300 |
| 10 | 300 | 200 |
+--------+--------+--------+
4 rows in set (0.00 sec)
以下是查询以计算跨数据库行的平均值-mysql> select avg(value1) as Value1_AVG,
> avg(value2) as Value2_AVG,
> avg(value3) as Value3_AVG
> from demo31;
这将产生以下输出-+------------+------------+------------+
| Value1_AVG | Value2_AVG | Value3_AVG |
+------------+------------+------------+
| 48.5000 | 153.7500 | 159.2500 |
+------------+------------+------------+
1 row in set (0.00 sec)
转播
