本文介绍了选择记录的第一个实例的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个表,myTable,其中有两个字段ID 和patientID.相同的患者 ID 可以使用不同的 ID 多次出现在表中.如何确保我只获得每个 patientID 的 ONE 实例?
I have a table, myTable that has two fields in it ID and patientID. The same patientID can be in the table more than once with a different ID. How can I make sure that I get only ONE instance of every patientID.?
我知道这不是完美的设计,但我需要从数据库和今天获取一些信息,然后再修复它.
I know this isn't perfect design, but I need to get some info out of the database and today and then fix it later.
推荐答案您可以将 CTE 与 ROW_NUMBER 函数:
You could use a CTE with ROW_NUMBER function:
WITH CTE AS( SELECT myTable.* , RN = ROW_NUMBER()OVER(PARTITION BY patientID ORDER BY ID) FROM myTable ) SELECT * FROM CTE WHERE RN = 1更多推荐
选择记录的第一个实例
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