Data cleaning: Difference between revisions

Jump to navigation Jump to search
382 bytes added ,  31 January 2018
Line 328: Line 328:
** one column data: [http://www.extendoffice.com/documents/excel/1499-count-duplicate-values-in-column.html How to count duplicate values in a column in Excel?] Using {{kbd | key = COUNTIF(range, criteria)}} {{access | date = 2015-08-25}} or using '''Pivot Tables'''(樞紐分析表)  to find the occurrence of value >= 2
** one column data: [http://www.extendoffice.com/documents/excel/1499-count-duplicate-values-in-column.html How to count duplicate values in a column in Excel?] Using {{kbd | key = COUNTIF(range, criteria)}} {{access | date = 2015-08-25}} or using '''Pivot Tables'''(樞紐分析表)  to find the occurrence of value >= 2
** two columns data: [https://support.microsoft.com/en-us/kb/213367 How to compare data in two columns to find duplicates in Excel] {{access | date = 2015-06-16}} {{exclaim}} It may costs too much time (larger than one hour) if the number of records exceeds 1,000,000
** two columns data: [https://support.microsoft.com/en-us/kb/213367 How to compare data in two columns to find duplicates in Excel] {{access | date = 2015-06-16}} {{exclaim}} It may costs too much time (larger than one hour) if the number of records exceeds 1,000,000
* [https://www.computerhope.com/unix/uuniq.htm uniq command] on Cygwin of {{Win}} or {{Linux}}: {{kbd | key=<nowiki>uniq -d <file.txt> > <duplicated_items.txt></nowiki>}}<ref>[https://unix.stackexchange.com/questions/52534/how-to-print-only-the-duplicate-values-from-a-text-file shell - How to print only the duplicate values from a text file? - Unix & Linux Stack Exchange]</ref>


* MySQL:  
* MySQL:  

Navigation menu