# How to handle duplicate entries in database **URL:** \ **Category:** Ignition\ **Created:** [July 6, 2020, 12:11pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382 "2020-07-06T12:11:33Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![warren.johnson](https://avatars.discourse-cdn.com/v4/letter/w/b9e5f3/32.png) [@warren.johnson](https://forum.inductiveautomation.com/u/warren.johnson)\ **Post date:** [July 6, 2020, 12:11pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/1 "2020-07-06T12:11:33Z")
I am far from a SQL expert and I am having an issue with duplicate entries. It only happens occasionally, but causes issues when searching. I have a OPC tag that triggers a write to the Database. When a new value is seen, it collects data from other OPC tags and throws it in the db. Sometimes the operator will have to run the part back through the machine and this will cause some new data, which I am okay with since they will use this data vs. the previous. However, when we are down for extended times, the last entry will populate in the db numerous times(not quite every hour) until a new value is seen. I was hoping for some assistance with this. I was going to use a check for the DMX. If the DMX value is new, then write all the data to the db. If the DMX is a duplicate, then only update the other data and not write a new entry. Here is my script so far. Thanks for any help. ````auto query = "INSERT INTO [Filler3_Data](dmx,pre_weight,filling_duration,position,dose_weight,post_weight,fault_code) VALUES (?,?,?,?,?,?,?)" dmx = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Status/DMX_Cell").value pre_weight = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Mes/P5110_Mes/Weight/Mes_w").value filling_duration = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Mes/P5120_Mes/Gen/Filling_Duration").value position = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Status/P5120_pos").value dose_weight = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Mes/P5140_Mes/Weight/Weight_dose").value post_weight = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Mes/P5140_Mes/Weight/Mes_w").value fault_code = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/DB_Results_0_/Status/Op_Fault_Number").value dbName = 'Prismatic_Data' values = [dmx, pre_weight, filling_duration, position, dose_weight, post_weight, fault_code] duplicate = system.tag.read("[default]SAFT/JAX/Workshop_2/Filling3/INPUTS/SCS_Result").value check = "SELECT COUNT(*) FROM [Filler3_Data] where dmx = '%s'" if currentValue != previousValue: system.db.runPrepUpdate(query, values, dbName, '', True, True) ``` ```` ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [July 6, 2020, 12:50pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/2 "2020-07-06T12:50:31Z")
> [@warren.johnson](#): > > if currentValue != previousValue: currentValue and previousValue are fully qualified. When you compare in your script it will run the prep update even if the values are the same but have different timestamps. I think you would want ```auto if currentValue.value != previousValue.value system.db.runPrepUpdate(query, values, dbName, '', True, True) ``` Also, put your tag reads into one single `system.tag.readAll()` as it will be more efficient. I would probably do this in a transaction group instead of a tag change event script, myself. ---
**Author:** ![warren.johnson](https://avatars.discourse-cdn.com/v4/letter/w/b9e5f3/32.png) [@warren.johnson](https://forum.inductiveautomation.com/u/warren.johnson)\ **Post date:** [July 6, 2020, 1:07pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/3 "2020-07-06T13:07:06Z")
Ahh, yes I didn’t think about digging down to the .value. That makes sense. I am not sure what you mean by the readALL statement. I haven’t used that and I haven’t used the transaction groups much either. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [July 6, 2020, 1:13pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/4 "2020-07-06T13:13:47Z")
I’m assuming you are using v7.9. [system.tag.readAll()](https://docs.inductiveautomation.com/display/DOC79/system.tag.readAll) and [transaction groups](https://inductiveuniversity.com/courses/transaction-groups/7.9) links ---
**Author:** ![warren.johnson](https://avatars.discourse-cdn.com/v4/letter/w/b9e5f3/32.png) [@warren.johnson](https://forum.inductiveautomation.com/u/warren.johnson)\ **Post date:** [July 6, 2020, 1:16pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/5 "2020-07-06T13:16:04Z")
8.0.9 and upgrading to 8.0.13 this month. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [July 6, 2020, 1:23pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/6 "2020-07-06T13:23:40Z")
Ah, yes v8 doesn’t have `readAll()` , `system.tag.read()` defaults to `system.tag.readBlocking()`, there is a `system.tag.readAsync()` also, but the transactions groups should be pretty much the same. either way, here is the [v8 link](https://inductiveuniversity.com/courses/transaction-groups-in-ignition/8.0) for the transaction groups. ---
**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:** [July 6, 2020, 1:28pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/7 "2020-07-06T13:28:04Z")
Both system.tag.read() and system.tag.readAll() are deprecated in v8. They still work for backward compatibility (for now), but are no longer in the documentation. Use system.tag.readBlocking(). And you _ **really** _ want to get them all at once if performance matters to you. ---
**Author:** ![warren.johnson](https://avatars.discourse-cdn.com/v4/letter/w/b9e5f3/32.png) [@warren.johnson](https://forum.inductiveautomation.com/u/warren.johnson)\ **Post date:** [July 6, 2020, 1:32pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/8 "2020-07-06T13:32:27Z")
Thanks for the help. Once production starts up, I will make sure that these changes work. ---
**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 6, 2020, 5:43pm UTC](https://forum.inductiveautomation.com/t/how-to-handle-duplicate-entries-in-database/36382/9 "2020-07-06T17:43:14Z")
If it wasn’t obvious, you want to add all of your tag paths to a list then pass the list to read Blocking to read them all at once, rather than multiple calls to the function