Question

我有一个下表（TBL_VIDEO），其中“ TIMESTAMP”中的列条目重复，并且我只想在“ CAMERA”数字匹配时将其删除。

之前：

ANALYSIS_ID | TIMESTAMP | EMOTION | CAMERA
-------------------------------------------    
 1          | 5         | HAPPY   | 1
 2          | 10        | SAD     | 1
 3          | 10        | SAD     | 1
 4          | 5         | HAPPY   | 2
 5          | 15        | ANGRY   | 2
 6          | 15        | HAPPY   | 2

之后：

ANALYSIS_ID | TIMESTAMP | EMOTION | CAMERA
-------------------------------------------    
 1          | 5         | HAPPY   | 1
 2          | 10        | SAD     | 1
 4          | 5         | HAPPY   | 2
 5          | 15        | ANGRY   | 2

我已经尝试过此语句，但是不会相应地删除列。感谢所有帮助您生成正确的SQL语句的帮助。预先感谢！

delete y
from TBL_VIDEO y 
where exists (select 1 from TBL_VIDEO y2 where y.TIMESTAMP = y2.TIMESTAMP and y2.CAMERA < y.CAMERA);

Answer 1

CREATE TABLE Table12
    ([ANALYSIS_ID] int, [TIMESTAMP] int, [EMOTION] varchar(5))
;

INSERT INTO Table12
    ([ANALYSIS_ID], [TIMESTAMP], [EMOTION])
VALUES
    (1, 5, 'HAPPY'),
    (2, 10, 'SAD'),
    (3, 10, 'SAD'),
    (4, 15, 'HAPPY'),
    (5, 15, 'ANGRY')
;

with cte as (select *, row_number() over (partition by emotion order by [ANALYSIS_ID] ) as rn   from Table12) 
delete from cte
where rn>1
select * from Table12

输出

ANALYSIS_ID TIMESTAMP   EMOTION
1              5         HAPPY
2              10         SAD
5              15        ANGRY

Answer 2

您有两个问题：

我的代码有什么问题
是否有更好的方法删除重复的列条目

第二个问题是重复。

关于第一个问题，请参阅https://docs.microsoft.com/en-us/sql/t-sql/statements/delete-transact-sql?view=sql-server-2017。（按上的F1键）。正确的语法是

delete y
from Table12 y 
where exists (

Answer 3

通用SQL命令如下。您可以输入列名/条件和表名。

从删除T （ SELECT ROW_NUMBER（）over（按列1分区，按列2排序）a，* FROM TABLENAME T 其中a> 1

Answer 4

删除来自TBL_VIDEO y 其中y.CAMERA <（选择y2.CAMERA 从TBL_VIDEO y2那里 y.TIMESTAMP = y2.TIMESTAMP）;

SQL-删除重复的列错误

4 个答案: