How can we delete duplicate rows in a table?

HAVING COUNT(*) > 1;

1. In the output above, we have two duplicate records with ID 1 and 3.
2. To remove this data, replace the first Select with the SQL delete statement as per the following query.
3. SQL delete duplicate Rows using Common Table Expressions (CTE)
4. We can remove the duplicate rows using the following CTE.

How can I delete duplicate rows in Excel?

Remove duplicate values

1. Select the range of cells that has duplicate values you want to remove. Tip: Remove any outlines or subtotals from your data before trying to remove duplicates.
2. Click Data > Remove Duplicates, and then Under Columns, check or uncheck the columns where you want to remove the duplicates.
3. Click OK.

How do I delete a duplicate record in SQL Server?

DELETE Duplicate Records Using ROWCOUNT So to delete the duplicate record with SQL Server we can use the SET ROWCOUNT command to limit the number of rows affected by a query. By setting it to 1 we can just delete one of these rows in the table. Note: the select commands are just used to show the data prior and after the delete occurs.

How do I remove duplicate pK values in SQL Server?

If there are only a few sets of duplicate PK values, the best procedure is to delete these manually on an individual basis. For example: The rowcount value should be n-1 the number of duplicates for a given key value. In this example, there are 2 duplicates so rowcount is set to 1.

How to delete duplicate rows in a table?

If you have rows that differ from each other, you can use an other method to delete duplicate rows in a table. For example if you have inserted date column and you want to keep the first rows inserted into the table by ordering due to the insert date column, you can use the ROW_NUMBER () OVER (PARTITION BY ORDER BY …) method.

How do you find the number of duplicates in SQL?

The first step is to identify which rows have duplicate primary key values: SELECT col1, col2, count(*) FROM t1 GROUP BY col1, col2 HAVING count(*) > 1. This will return one row for each set of duplicate PK values in the table. The last column in this result is the number of duplicates for the particular PK value.