# I like to create a querry tag in an UDT using a parameter resulting in an error

**URL:** <https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169>\
**Category:** Ignition\
**Created:** [June 26, 2026, 12:31pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169 "2026-06-26T12:31:40Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![markus.deutsch](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@markus.deutsch](https://forum.inductiveautomation.com/u/markus.deutsch)\
**Post date:** [June 26, 2026, 12:31pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/1 "2026-06-26T12:31:41Z")

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HI!  
I'm want to query the name of a machine from a mySQL-DB in an UDT using a parameter (Ignition 8.3.4).  
The Parameter is defined as a string with the value `machineCode1`(Without any ' )

```sql
SELECT machineName 
FROM table 
WHERE machineCode = {parameter1}

```

The Tag results in the following error: Error\_ExpresionEval("Unknown column 'machineCode1' in 'where clause'")

If I read the tag in a script with`system.tag.readBlocking(`machine1/Parameters.parameter1", 100)[0].value`)` and use the same query in a `system.db.runPrepQuery()` it returns the correct value.

If I replace `{paramter}` with `'machineCode1'` directly the querry tag returns the correct name.  
If I set `{paramter}` to `'machineCode1'` (with the ') the query also returns the correct name, but the scripts do not return anything anymore (which makes sense, as the DB does not have an entry with ' )

What am I missing? Is this an inconsistency in type handling?

Thanks for your Input!

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**Author:** ![tgarrison](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/tgarrison/32/80965_2.png) [@tgarrison](https://forum.inductiveautomation.com/u/tgarrison)\
**Post date:** [June 26, 2026, 12:53pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/2 "2026-06-26T12:53:24Z")

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that error would indicate it's looking for a column(field) with the name machineCode1. Which makes me think you're query isn't actually the query that is running. what are the actual column names in your table?

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**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [June 26, 2026, 1:11pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/3 "2026-06-26T13:11:00Z")

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I would suggest you make a named query and pass the parameter to it that way

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**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [June 26, 2026, 1:20pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/4 "2026-06-26T13:20:40Z")

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I don't use query tags, but does this work?

```python
SELECT machineName 
FROM table 
WHERE machineCode = '{parameter1}'

```

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<div class="post-metadata">

**Author:** ![markus.deutsch](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@markus.deutsch](https://forum.inductiveautomation.com/u/markus.deutsch)\
**Post date:** [June 29, 2026, 12:30pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/6 "2026-06-29T12:30:11Z")

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Not sure why I didn't try this, but it works!

Thanks!

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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:** [June 29, 2026, 1:36pm UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/7 "2026-06-29T13:36:28Z")

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Be aware that having to quote a parameter indicates that the query is susceptible to SQL injection attacks. You should avoid query tags that need string parameters.

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<div class="post-metadata">

**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\
**Post date:** [July 1, 2026, 4:04am UTC](https://forum.inductiveautomation.com/t/i-like-to-create-a-querry-tag-in-an-udt-using-a-parameter-resulting-in-an-error/116169/8 "2026-07-01T04:04:12Z")

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> [@pturmel](#):
>
> You should avoid query tags

Probably could stop here tbh 🙂