Iterate through database result table

  • 21 July 2023
  • 2 replies

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With the help of the database standard modules I do a select on a database table.
I want to iterate through all rows returned by the select and do stuff.

The only thing I found is this:

From a performance perspective this solution doesn't seem good. The SQL statement gets executed over and over again for each iteration. When it's a time intensive SQL statement you shouldn't do that. Actually you shouldn't do this even when it's not :)

Any idea on how to execute the SQL statement just once and iterate through all lines?

I saw in the documentation that you can export the result table content to a csv file. But I didn't find how to then read the csv file line by line and do stuff...


Best answer by Community Administrator 21 July 2023, 11:42

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Userlevel 4
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For some users the following solution worked:

I created my own "Special Execution Task" with C#:



The following call of this module will create buffers with the result values in the form of:

sql_Count: Number of result lines, so that I can iterate through all of them

sql_Column1_[Row Number]

sql_Column2_[Row Number]

Where [Row Number] is a number from 1 to the maximum number of result lines 



Solves all of my issues: The SQL statement is execute just once. I automatically have all the values in buffers so that I can use them later...

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Another possible solution would be to first download the result in a csv and then load it into caching database, then verify the data as per your needs would be faster. Of course the SET is a smarter solution.