如何在 MySQL 中计算跨数据库行平均值？

为此，你可以使用 AVG()。语法如下 −

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
−> );
Query OK, 0 rows affected (2.27 sec)

使用插入命令向表中插入一些记录 −

mysql> insert into demo31 values(34,55,67);
Query OK, 1 row affected (0.27 sec)

mysql> insert into demo31 values(50,60,70);
Query OK, 1 row affected (0.16 sec)

mysql> insert into demo31 values(100,200,300);
Query OK, 1 row affected (0.14 sec)

mysql> insert into demo31 values(10,300,200);
Query OK, 1 row affected (0.15 sec)

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)

以下是计算跨数据库行平均值的查询 −

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)

更新于： 2020-11-19

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