# Returning 't\_stamp' from tag query

**URL:** <https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [November 2, 2024, 3:00am UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078 "2024-11-02T03:00:43Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Tyler\_Folsom](https://avatars.discourse-cdn.com/v4/letter/t/8797f3/32.png) [@Tyler\_Folsom](https://forum.inductiveautomation.com/u/Tyler_Folsom)\
**Post date:** [November 2, 2024, 3:00am UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078/1 "2024-11-02T03:00:43Z")

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Hello,

My end goal is to find the closing reading at the end of a month.

I have tried the **system.tag.queryTagCalculations** and **system.tag.queryTagHistory** functions. I know **system.tag.queryTagCalculations** will not return the 't\_stamp' along with the calculation. The 't\_stamp' returned using **system.tag.queryTagHistory** is always returning the first day of the month at noon (ex. 10/01 12:00).

```python
october_1 = system.tag.queryTagCalculations(paths=[path], calculations=['Maximum'], startDate=start_1, endDate=end_1)
october_1_value = october_1.getValueAt(0,1)

october_2 = system.tag.queryTagHistory(paths=[path], startDate=start_1, endDate=end_1, returnSize=1, aggregationMode="Maximum", returnFormat='Wide')
october_2_timestamp = october_2.getValueAt(0,0)
october_2_formatted_timestamp = system.date.format(october_2_timestamp, "MM/dd hh:mm")
october_2_value = october_2.getValueAt(0,1)

```

I see if I make 'returnSize' bigger than 1 then I can get other 't\_stamp' values to be returned but I am not sure how large to make 'returnSize'.

Is there something simple I am bypassing here?

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [November 2, 2024, 11:59am UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078/2 "2024-11-02T11:59:01Z")

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I'm not super comfortable with the history query functions, they're... weird. Or rather, they often return unexpected results.  
But you should probably remove the `aggregationMode` parameter, if what you want is the last record of the month.

Another approach would be to skip the built-in functions entirely and go straight for the database.  
Even if you end up using the `queryTagHistory` function, because that's probably the way to go, it can help you validate the results (I often check the tables directly to make sure the functions aren't messing with me.)  
You can find the right partition in the `sqlth_partitions` table, by checking that the last day of the month is between the partition's `start_time` and `end_time`.  
Then go fetch the record from that partition.

I know it may sound weird going through that trouble, because it seems obvious that passing the first and last day of the month as a parameter to `queryTagHistory` then grabbing the last record returned should be enough, but I've just seen to much weird stuff with that function that I don't trust it blindly anymore.

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<div class="post-metadata">

**Author:** ![Tyler\_Folsom](https://avatars.discourse-cdn.com/v4/letter/t/8797f3/32.png) [@Tyler\_Folsom](https://forum.inductiveautomation.com/u/Tyler_Folsom)\
**Post date:** [November 2, 2024, 12:23pm UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078/3 "2024-11-02T12:23:23Z")

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Thank you for your thoughts. I had considered skipping the built-in functions but I was hesitant because it would require extra code by scanning the 'sqlth\_drv' table, retrieving the proper 'tagid', and then correctly constructing the table name that houses the data (ex. 'sqlt\_data\_ **2** _ **2024** _ **10**').

This is also easy to do in python.

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<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [November 2, 2024, 4:59pm UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078/4 "2024-11-02T16:59:20Z")

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> [@Tyler\_Folsom](#):
>
> correctly constructing the table name that houses the data (ex. 'sqlt\_data\_ **2** _ **2024** _ **10**')

You don't have to build it, you can fetch it from the `sqlth_partitions` table.

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<div class="post-metadata">

**Author:** ![Tyler\_Folsom](https://avatars.discourse-cdn.com/v4/letter/t/8797f3/32.png) [@Tyler\_Folsom](https://forum.inductiveautomation.com/u/Tyler_Folsom)\
**Post date:** [November 4, 2024, 2:13pm UTC](https://forum.inductiveautomation.com/t/returning-t-stamp-from-tag-query/98078/5 "2024-11-04T14:13:10Z")

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Thanks again for your input. I was able to grab the tags and timestamps for the report.  
A bit of coding was required because tags are spread among different drives.

I had to fetch a tag from a custom database table, find which drive the tag is stored within which helps with knowing the partition.