finding duplicate rows counts by keeping all rows
31119
Count number of rows per group and add result to original data frame
4994
Retrieving n rows per group
26104
How do you count the number of occurrences of a certain substring in a SQL varchar?
5653
Fastest way to count occurrences of each unique element
34883
Remove specific duplicates (all but latest)
139237
How to sum over duplicates?
80577
How to delete duplicates on a MySQL table?
62624
What is a simple and efficient way to find rows with time-interval overlaps in SQL?
128373
How do I delete unique rows from a table with duplicate keys?
91887
Select statement to find duplicates on certain fields
57566
SQL to find the number of distinct values in a column
53689
Filtering out duplicated/non-unique rows in data.table
64725
Calculate row value based on previous and actual row values
67770
MySQL: Count the distinct rows per day
19627
Column count doesn't match value count at row 1
19952
Counting DISTINCT over multiple columns
113049
How to delete duplicate rows in SQL Server 2008?