[SQL ] 请问这两个语法结果一样吗?

楼主: evilove (愿意感动就是一种享受)   2016-06-17 11:12:59
数据库名称:MySQL
内容/问题描述:您好我是初学者,想知道下面两个语法的结果是一样的吗?
谢谢!
SELECT COUNT(DISTINCT pid) AS Hispanic
FROM (SELECT patients.pid, patients.ethnicity, ethnicity.Name, ethnicity.Code
FROM ethnicity
INNER JOIN patients
ON patients.ethnicity=ethnicity.Code)
WHERE Name='Hispanic or Latino';
SELECT COUNT(DISTINCT patients.pid) AS Hispanic
FROM ethnicity, patients
WHERE patients.ethnicity=ethnicity.Code
AND ethnicity.Name='Hispanic or Latino';
作者: Ammenze (蓝天白云)   2016-06-17 12:19:00
应该是一样的
楼主: evilove (愿意感动就是一种享受)   2016-06-17 23:16:00
谢谢您~

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