# Run a query on one block

**URL:** https://discourse.paraview.org/t/run-a-query-on-one-block/16098
**Category:** Development
**Created:** [February 3, 2025, 8:33am UTC](https://discourse.paraview.org/t/run-a-query-on-one-block/16098 "2025-02-03T08:33:42Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![jeDuck](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/898d66/32.png) [@jeDuck](https://discourse.paraview.org/u/jeDuck)
#### Post date: [February 3, 2025, 8:33am UTC](https://discourse.paraview.org/t/run-a-query-on-one-block/16098/1 "2025-02-03T08:33:43Z")

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Dear Paraview developers,  
is it possible in Paraview to create a query-based selection on a set of blocks? For example, I have a multiblock, consisting of two blocks and I want to find point with maximum value in a single block. If not, how can one add custom selection queries to source code?

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 5, 2025, 9:16am UTC](https://discourse.paraview.org/t/run-a-query-on-one-block/16098/2 "2025-02-05T09:16:22Z")

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> [@jeDuck](#):
>
> I want to find point with maximum value in a single block.

View → FindData should let you do that.

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### Author: ![jeDuck](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/898d66/32.png) [@jeDuck](https://discourse.paraview.org/u/jeDuck)
#### Post date: [February 6, 2025, 4:14pm UTC](https://discourse.paraview.org/t/run-a-query-on-one-block/16098/3 "2025-02-06T16:14:08Z")

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I tried to use Block Selectors in Find Data to implement that, but that didn’t work. Let’s say, for example, that I have 2 blocks , first one has 100 points, second has 50 points and I want to find maximum ID in block. If I set “ID is maximum” and block 1 in block selectors, it returns point with ID 100, if I set “ID is maximum” and block 2 in block selectors, it returns nothing because maximum ID is not in block 2. I want it to return ID 100 in block 1 and return ID 50 in block 2.

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 7, 2025, 8:35am UTC](https://discourse.paraview.org/t/run-a-query-on-one-block/16098/4 "2025-02-07T08:35:58Z")

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Indeed, you need to split by block first, using ExtractBlock.