select DISTINCT
时间: 2023-11-03 07:55:50 浏览: 141
SELECT DISTINCT语句用于返回唯一不同的值。在表中,一个列可能会包含多个重复值,有时您也许希望仅仅列出不同(distinct)的值。使用DISTINCT关键字可以实现这一目的。例如,可以使用SELECT DISTINCT来查询表中不同的值,并返回结果集中的唯一值。根据需要,可以对一个或多个列使用DISTINCT关键字来获取不同的值。通过使用SELECT DISTINCT语句,可以过滤掉结果集中重复的数据,让查询结果更加清晰和准确。
相关问题
select distinct
select distinct是一种SQL查询语句,用于从数据库中选择不重复的行。它可以应用于一个或多个列,以确保查询结果中的每一行都是唯一的。\[1\]例如,使用select distinct可以查询出所有不同的id、name或其他列的值。如果在where子句中使用select distinct并且没有返回结果,那么查询结果将为空。\[2\]另外,使用select distinct还可以选择特定的字段进行筛选,只返回所需的字段的查询结果。\[3\]
#### 引用[.reference_title]
- *1* *2* [select distinct 语句详解](https://blog.csdn.net/good_good_xiu/article/details/115399279)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
- *3* [5. Select/Select distinct语句以及Where子句的写法](https://blog.csdn.net/zyypjc/article/details/127050051)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
[ .reference_list ]
Select distinct
" DISTINCT" is a SQL statement used to retrieve unique or distinct values from a database table. It eliminates any duplicate rows that might exist in the result set.
For example, if you have a table named "customers" with columns "id", "name", and "email", you can use the following SQL query to retrieve a list of distinct email addresses:
```
SELECT DISTINCT email FROM customers;
```
This would return a list of unique email addresses from the "customers" table.
阅读全文