Deletes the specified duplicate record in SQL Server data.

Deletefrom table where primary key (selecttop1 primary key from table where same field (select same field from Table groupby same field havingcount (*) 1) primary key is a field with no repeated values in the table, for example, automatic incremental ID; for the same fields, such as collection time, this statement deletes records with the same collection time in the table.

Delete from table where primary key = (select top 1 primary key from table where same field = (select same field from Table group by same field having count (*) 1 )) A primary key is a field with no repeated values in the table, such as an automatic incremental ID. This statement deletes records with the same fields, such as the collection time and the same collection time in the table.

Delete from table where primary key = (select top 1 primary key from table where same field = (select same field from Table group by same field having count (*)> 1 ))

A primary key is a field with no repeated values in the table, such as an automatic incremental ID;

Delete records with the same collection time for the same fields, such as "collection time ".

This statement can only delete one duplicate record each time it is executed. If three records have the same "collection time", the statement must be executed cyclically twice.