Read rows from SQLite DB and prompt user to select a value to use as a flow variable

[Mirri]

Hi All,

First up, unfortunately i am not able to download example workflows, so i am hoping someone can describe a solution.

I have a table in an SQLite database which contains records grouped by a date value.

I want to read the date column from this table, make the values distinct and sorted descending order (normally i would do both of these things via SQL, but explicitly including as steps here in case i need to do these things differently) and then prompt the user to select one of the date values from a drop-down list.

Further downstream in the flow, i want to use the selected value as a flow variable to get all records from the table which have that value in the date column.

I have tried selecting and reading from the date column in my table and then passing to a Value Selection Widget or a Nominal Row Filter Widget, but both of these give me error messages either about no columns with domain information or no column available for selection in input table.

Can anyone assist?

Many thanks

Mirri

[ipazin]

Hello @Mirri,

you need Domain Calculator node with Restrict number of possible values option un-selected for a Value Selection Widget or a Nominal Row Filter Widget nodes to work.

See here for additional explanation:

Nominal Value Row Filter - Issue on limitation of values

Hi, I can’t look at your workflow since I am on mobile, but the problem should be easy to fix. Generally KNIME stores possible values of nominal columns, but only up to 60 unique values. If there are more, possible values are not stored. In the domain calculator under possible values you can specify in the bottom left, if my memory serves me right, how many values values should be stored. This overwrites the maximum of 60 for the table coming into the domain calculator. So just change that valu…

Br,
Ivan

[Mirri]

Thank you, this solved my issue!

Mirri