Historian writing null values to DB

Ignition
1

Hello,

I am having an issue I can seem to figure out. I have set up history enabled tags that were working without an issue. Now all of my tags are writing null values to the database. I set up a table with a tag history binding and the table is showing my current value and then jumps to last recorded good value, nothing in between. I have a good DB connection and nothing in the store and forward. I see the INSERT queries on the gateway, and the DB tables are updating with new rows, but the float values are null.

2

It doesn't display because null is essentially empty.

Try using a coalesce to insert a default value where null
coalesce

or you can use isNull as well.
isNull

3

Have you checked using the Database query browser on the designer. If the tag is an integer it will write floats as null in the float column while filling in the int column

4

I found the solution in the forum.

Strange behavior with partitioned historian data tables

I originally had the project running on my laptop before transferring it over to a different PC. A second table was created. "sqlt_data_3_2023_06". I removed all the tables and restarted the gateway. Everything is working again.

I didn't need the information that was recorded so this wasn't a big deal taking this approach but it would be nice to have a better a solution so the data could be saved if I were to ever run into something similar in the future. Is it as simple as deleting the two extra entries in "sqlth_drv"?