Shulou(Shulou.com)06/01 Report--

This article introduces the knowledge of "how to delete duplicate lines in some fields of big data file under Linux". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Recently wrote a data acquisition program to generate a file containing more than 10 million rows of data, the data is composed of four fields, according to the requirements need to delete the second field duplicate row, looking for linux also did not find a suitable tool, sed/gawk and other stream processing tools can only deal with one line per line, and can not find duplicate fields of the row. It seems that I have no choice but to python a program. I suddenly remembered to use mysql, so I made a big shift:

1. Import data into the table using mysqlimport-- local dbname data.txt. The table name should be the same as the file name.

two。 Execute the following sql statement (unique fields are required to be uniqfield)

The code is as follows:

Use dbname

Alter table tablename add rowid int auto_increment not null

Create table t select min (rowid) as rowid from tablename group by uniqfield

Create table T2 select tablename. * from tablename,t where tablename.rowid= t.rowid

Drop table tablename

Rename table t2 to tablename

This is the end of the introduction of "how to delete duplicate lines in some fields in big data file under Linux". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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