如何在不合并 SQL 服务器中的行的情况下创建一个显示另一列中的值出现次数的列
How to create a column that shows the number of times a value in another column appears without combining rows in SQL Server
我有一个如下所示的数据库：
+----------------+
| Account Number |
+----------------+
| A0001 |
| A0001 |
| A0001 |
| A0002 |
| A0003 |
| A0003 |
+----------------+
我需要在不更改行数的情况下创建一个包含帐号出现次数的列。
我知道
SELECT Account Number, COUNT(*) AS Counts
FROM database
GROUP BY Account Number
returns
+----------------+--------+
| Account Number | Counts |
+----------------+--------+
| A0001 | 3 |
| A0002 | 1 |
| A0003 | 2 |
+----------------+--------+
但我需要这样的东西：
+----------------+--------+
| Account Number | Counts |
+----------------+--------+
| A0001 | 3 |
| A0001 | 3 |
| A0001 | 3 |
| A0002 | 1 |
| A0003 | 2 |
| A0003 | 2 |
+----------------+--------+
我正在使用 Microsoft SQL 服务器。
您可以在此处将计数用作 window function：
Select AccountNumber,
count(*) over (partition by AccountNumber) as counts
from Table
我有一个如下所示的数据库：
+----------------+
| Account Number |
+----------------+
| A0001 |
| A0001 |
| A0001 |
| A0002 |
| A0003 |
| A0003 |
+----------------+
我需要在不更改行数的情况下创建一个包含帐号出现次数的列。
我知道
SELECT Account Number, COUNT(*) AS Counts
FROM database
GROUP BY Account Number
returns
+----------------+--------+
| Account Number | Counts |
+----------------+--------+
| A0001 | 3 |
| A0002 | 1 |
| A0003 | 2 |
+----------------+--------+
但我需要这样的东西：
+----------------+--------+
| Account Number | Counts |
+----------------+--------+
| A0001 | 3 |
| A0001 | 3 |
| A0001 | 3 |
| A0002 | 1 |
| A0003 | 2 |
| A0003 | 2 |
+----------------+--------+
我正在使用 Microsoft SQL 服务器。
您可以在此处将计数用作 window function：
Select AccountNumber,
count(*) over (partition by AccountNumber) as counts
from Table