SQL Server partition function partition by and group by difference Delete key field repeating column

The partition by keyword is part of an analytic function that differs from an aggregate function (such as group by) in that it can return multiple records in a group, whereas aggregate functions generally have only one record that reflects the statistic value.

Partition by is used to group the result set, and if not specified, it takes the entire result set as a grouping.

Partition by differs from group by in that the former returns each piece of data in the group and can sort the grouped data. The latter can only return records for the data statistics values of the group after aggregation.

Usage: Select *,row_number () over (partition by Name order by score) as NewRow
From table

Delete a key field repeating column

@newtable---table name

@key-Self-added columns

@repeate---The key fields for duplicate checking

Delete ' [email protected]+ ' WHERE ' [email protected]+ ' In (select ' [E-mail protected]+ ' from (select *,rank () over (Partit Ion by ' [E-mail protected]+ ' ORDER by ' [email protected]+ '] as newrow from ' [email protected]+ ') NT where nt.newrow>1)

SQL Server partition function partition by and group by difference Delete key field repeating column