# Transaction group issue – Block group using previous / buffered data

**URL:** <https://forum.inductiveautomation.com/t/transaction-group-issue-block-group-using-previous-buffered-data/41019>\
**Category:** Ignition\
**Tags:** ignition79\
**Created:** [November 27, 2020, 5:35pm UTC](https://forum.inductiveautomation.com/t/transaction-group-issue-block-group-using-previous-buffered-data/41019 "2020-11-27T17:35:26Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [November 27, 2020, 6:19pm UTC](https://forum.inductiveautomation.com/t/transaction-group-issue-block-group-using-previous-buffered-data/41019/2 "2020-11-27T18:19:22Z")

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This is a known issue:

> [@Writing Variable Number Of Rows to PLC Array](http://forum.inductiveautomation.com/t/writing-variable-number-of-rows-to-plc-array/32637):
>
> I am trying to use a block group to write a variable number of rows from a SQL database to my PLC array using the SQL Bridge Module. The problem is that if the results is less than the last query, then it will fill the array with the new data and entries from the old data. Is there a way to clear the block data after it writes to the PLC?

There doesn't seem to be a bug number in the post. You may want to contact support to see where this stands. (You will certainly have to upgrade Ignition for any fix, once available.) The workaround would be to replicate your transaction group functionality with a script.

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