Question

大家好我正在尝试获取所有记录而不重复。

这里是我的示例数据库记录。

   (`id`, `productName`, `description`)
   -----------------------------------------------
   (1, 'OpenIDM', 'Platform for building enterprise provisioning solutions'),
   (2, 'OpenAM', 'Full-featured access management'),
   (3, 'OpenDJ', 'Robust LDAP server for Java'),
   (4, 'OpenDJ', 'Robust LDAP server for Java')  !!This line should not appear after SQL result

我想用SQL获得什么

   (`id`, `productName`, `description`)
   -----------------------------------------------
   (1, 'OpenIDM', 'Platform for building enterprise provisioning solutions'),
   (2, 'OpenAM', 'Full-featured access management'),
   (3, 'OpenDJ', 'Robust LDAP server for Java'),

以下是此主题的SQL代码段。

select productName 
from ForgeRock
WHERE productName in (select productName from ForgeRock group by productName having count(*)>1)

http://sqlfiddle.com/#!9/6c924/121

如何在不重复的情况下获取所有元素？谢谢你的帮助。

Answer 1

一种方法是获取最小id

的数据

select min(`id`),`productname`,`description` from forgerock
group by `productname`, `description`

Answer 2

对id的值有特殊要求吗？

一个简单的MIN()函数可以解决这个问题

SELECT MIN(`id`),
  `productName`,
  `description`
FROM ForgeRock
GROUP BY `productName`, `description`

Answer 3

我认为你必须使用DISTINCT

select distinct productName,description from ForgeRock;

这是小提琴的结果：
http://sqlfiddle.com/#!9/6c924/132

如何获取所有记录而不重复

3 个答案: