# Import only delta (differences) from csv into mysql **URL:** \ **Category:** Logstash\ **Created:** [November 16, 2021, 8:54am UTC](https://discuss.elastic.co/t/import-only-delta-differences-from-csv-into-mysql/289283 "2021-11-16T08:54:20Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Mihai\_Stuparu](https://avatars.discourse-cdn.com/v4/letter/m/bc8723/32.png) [@Mihai\_Stuparu](https://discuss.elastic.co/u/Mihai_Stuparu)\ **Post date:** [November 16, 2021, 8:54am UTC](https://discuss.elastic.co/t/import-only-delta-differences-from-csv-into-mysql/289283/1 "2021-11-16T08:54:20Z")
Hello, I am using logstash to call an API (input), save it as .csv (filter) and upload it into a mysql table (output). All is good. But I need to do it each day (or each night rather): call that API, get the .csv and upload it in mysql. For uploading I am using a simple: statement =\> INSERT INTO ... VALUES. This will duplicate the existing entries. The question is: which is your advise, the best practice, to only upload the delta, the differences: so what is new in .csv file, but does not already exists in mysql. I don't have primary keys on mysql, probably I need to create one from 3 columns, there is no id, no unique identifier, rows values can appear multiple time. Example of the data from csv\mysql: ColumnA ColumnB ColumnC ColumnD ColumnE ValueA ValueB ValueC ValueD ValueE ValueA ValueB ValueC1 ValueD1 ValueE ValueA ValueB ValueC ValueD1 ValueE1 ValueA ValueB1 ValueC2 ValueD2 ValueE2 ---
**Author:** ![AquaX](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/aquax/32/92006_2.png) [@AquaX](https://discuss.elastic.co/u/AquaX)\ **Post date:** [November 17, 2021, 1:19pm UTC](https://discuss.elastic.co/t/import-only-delta-differences-from-csv-into-mysql/289283/2 "2021-11-17T13:19:45Z")
Yes, create a primary key and then put a constraint on that column in the SQL database so that it will not insert a duplicate. It will throw an error when you do try to do that but that error can be caught and discarded. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [December 15, 2021, 1:20pm UTC](https://discuss.elastic.co/t/import-only-delta-differences-from-csv-into-mysql/289283/3 "2021-12-15T13:20:04Z")
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