我对 SQL 服务器相当陌生(这是我在 StackOverflow 上的第二篇文章)。我目前正在使用 SQL Server 2008 R2。我有几个表已加入以下查询:
SELECT pt.first_name, pt.last_name, pt.provider_id,
pt.last_visit_date, pl.last_name
FROM dbo.pm_patient pt
INNER JOIN dbo.ProviderList pl
ON pt.provider_id = pl.provider_id
WHERE pt.last_visit_date >= '02/01/2012' AND pt.last_visit_date <= '02/01/2013'
ORDER BY provider_id
上述查询的结果如下所示:
first_name last_name provider_id last_visit_date last_name
Smith John 1 04/25/2012 Johnson
Doe Jane 1 02/25/2012 Johnson
Davies Ann 1 03/15/2012 Johnson
Dupree David 1 11/20/2012 Johnson
Jones Becky 1 04/21/2012 Smith
Diaz Mike 1 02/12/2012 Smith
Williams Allison 1 08/05/2012 Smith
Taylor Joe 1 10/01/2012 Smith
我宁愿简单地得到以下结果:
last_name NoOfPatients
Johnson 4
Smith 4
有人可以帮我吗?