# Query coding with Dynamic Column naming **URL:** \ **Category:** Ignition\ **Tags:** scripting\ **Created:** [September 8, 2025, 11:27pm UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471 "2025-09-08T23:27:50Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Bill\_Huang](https://avatars.discourse-cdn.com/v4/letter/b/b4bc9f/32.png) [@Bill\_Huang](https://forum.inductiveautomation.com/u/Bill_Huang)\ **Post date:** [September 8, 2025, 11:27pm UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/1 "2025-09-08T23:27:50Z")
Hi guys, I’m trying to get the contents in a certain column referring to the name of the row in a table. My code is following: ```python def valueChanged(tag, tagPath, previousValue, currentValue, initialChange, missedEvents): Target_Column_SQL = "[.]Station_ID" Name = "[.]Name" Trainer = "[.]Trainner_Log_In" Level = "[.]Training_Level" sourceTagPath = "[.]Badge" database = 'DW_SCADA_MSSQL' badgeRead = system.tag.readBlocking([sourceTagPath])[0].value target = system.tag.readBlocking([Target_Column_SQL])[0].value ReadResult = [] if currentValue.value != "0": query = "SELECT Badge, employee_name, [{0}]] FROM Training_Matrix WHERE Badge = ?".format(target) ReadResult = system.db.runPrepQuery(query, [badgeRead], database) if ReadResult: system.tag.writeBlocking([Name], [ReadResult[0][1]]) system.tag.writeBlocking([Level], [ReadResult[0][2]]) if ReadResult[0][1] in ('Khuc, Hoa The', 'Osorno, Hector', 'Imafidon-Taiwo, Shogbolu', 'Janapareddy, Sreedhar'): system.tag.writeBlocking([Trainer], [True]) else: system.tag.writeBlocking([Name], ["User Not Found"]) system.tag.writeBlocking([Level], [""]) ``` The script attached to a child tag to my UDT as following: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/4/b47c1638fbf68f57600737a38e0170537c2b0757.png) For some reason the script would not work as I expected. But when I remove the dynamic element [{0}] and .format(target) then replace with solid name “WL\_OP10\_30“ in the following code, the script works. ```python query = "SELECT Badge, employee_name, [{0}]] FROM Training_Matrix WHERE Badge = ?".format(target) ``` ```python query = "SELECT Badge, employee_name, WL_OP10_30 FROM Training_Matrix WHERE Badge = ?" ``` Can anyone give me some clue? \*\*Sorry for the confusing if the layout doesn't make sense. ---
**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\ **Post date:** [September 8, 2025, 11:39pm UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/2 "2025-09-08T23:39:26Z")
I don't understand the syntax, but have you an error in `[{0}]]`? The square bracket counts are different. ---
**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:** [September 9, 2025, 1:18am UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/3 "2025-09-09T01:18:21Z")
It is unsafe to run database queries in tag `valueChange()` event scripts. (Only updates through the S&F subsystem are safe.) Move all of this code to a gateway tag change event script (project, not on a tag). Anything that might cause a script to take more than a handful of milliseconds risks locking up all tag event scripting. ---
**Author:** ![Bill\_Huang](https://avatars.discourse-cdn.com/v4/letter/b/b4bc9f/32.png) [@Bill\_Huang](https://forum.inductiveautomation.com/u/Bill_Huang)\ **Post date:** [September 9, 2025, 1:37am UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/4 "2025-09-09T01:37:18Z")
Sorry that was a mistake. I have removed it but nothing changes ---
**Author:** ![Bill\_Huang](https://avatars.discourse-cdn.com/v4/letter/b/b4bc9f/32.png) [@Bill\_Huang](https://forum.inductiveautomation.com/u/Bill_Huang)\ **Post date:** [September 9, 2025, 1:42am UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/5 "2025-09-09T01:42:31Z")
Thank you for the reply, it’s good to know. I have moved all these code to script gatway event, but it still doesn't work. Btw, I have another tag with the same code in tag valuechange event, and it works fine. The different between these 2 tags are the data type. The one with script working is an individual OPC tag, while the one has the problem is one of the child tag of a UDT which contains a few tags in different data type ---
**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:** [September 9, 2025, 2:41am UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/6 "2025-09-09T02:41:24Z")
Unrelated, but you also should not be reading and writing to single tags sequentially with multiple calls to system.tag.\*; multiple reads/writes should always be done in a single call by supplying a list, for efficiency, otherwise you're building artificial scalability limits into your application ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [September 9, 2025, 8:54am UTC](https://forum.inductiveautomation.com/t/query-coding-with-dynamic-column-naming/110471/7 "2025-09-09T08:54:26Z")
Can you share the error from the logs?