SQL - 删除重复的结果

Question

我有一个看起来像这样的表：

name     | surname<br>
John     |  John<br>
Jessica  |  Madson<br>

我有这样的查询：

SELECT * FROM table WHERE name LIKE '%j%' OR surname LIKE '%j%'

我得到了什么：

John John
John John
Jessica Madson

我想要的是什么：

John John
Jessica Madson

如何摆脱重复的结果？

Answer 1

使用DISTINCT：

SELECT DISTINCT name, surname
FROM yourtable
WHERE name LIKE '%j%' OR surname LIKE '%j%'

Answer 2

尝试：

SELECT DISTINCT name, surname FROM table WHERE name LIKE '%j%' OR surname LIKE '%j%'

Answer 3

你也可以使用group by

SELECT name, surname
FROM yourtable
WHERE name LIKE '%j%' OR surname LIKE '%j%'
GROUP BY name, surname

Answer 4

您可以在SQL Server中使用DISTINCT仅获取不同的记录。除此之外，您还可以使用ROW_NUMBER (Transact-SQL)函数，通过将数字分配给结果集来获得不同的结果。

row_number()的语法如下所示。

ROW_NUMBER ( )   
    OVER ( [ PARTITION BY value_expression , ... [ n ] ] order_by_clause )

下面是实现。

Create table TempTable (name varchar(50), surname varchar(50))

Insert into TempTable Values 
               ('John', 'John')
             , ('John', 'John') 
             , ('Jessica', 'Madson')
             , ('Jessica', 'Madson') 
             , ('Suraj', 'Kumar')
             , ('Peter', 'Smith')

Select * from TempTable -- All records.

Select * from(
SELECT name
       ,surname
       ,row_number() over (partition by name, surname order by name, surname) as RN -- For partition
FROM TempTable
WHERE name LIKE '%j%' OR surname LIKE '%j%'
)temp
where RN = 1 -- For Distinct records only

输出将如下所示：

您可以在-db<>fiddle

处找到演示。