SQL statement for querying and deleting duplicate records (1/4)

SQL statement for querying and deleting duplicate records

(1)
For example
There is a field "name" in Table ",
The "name" value may be the same for different records,
Now, you need to query repeated items in the "name" value between the records in the table;

Select name, count (*) from a group by name having count (*)> 1
If the gender is also the same, the statement is as follows:
Select name, sex, count (*) from a group by name, sex having count (*)> 1

 

(2)
Method 1

Declare @ max integer, @ id integer
Declare cur_rows cursor local for select Main field, count (*) from table name group by main field having count (*)>; 1
Open cur_rows
Fetch cur_rows into @ id, @ max
While @ fetch_status = 0
Begin
Select @ max = @ max-1
Set rowcount @ max
Delete from table name where primary field = @ id
Fetch cur_rows into @ id, @ max
End
Close cur_rows
Set rowcount 0

Method 3

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