topic Re: How to preserve numeric column types when concatenating tables with empty columns in Discussions

How to preserve numeric column types when concatenating tables with empty columns

SophieCuvillier — Thu, 27 Nov 2025 15:43:52 GMT

Hello,

I have two tables ((imported from csv files initially) that I want to concatenate, each containing only one column, “Column 1” (see screenshot below). In the first table, there is no data; it is empty and of the Nominal character type (defaut, when exporting the csv).

In the second table, there is numerical data.

When I concatenate the two tables, the final format is nominal character even though there is numerical data.

Is there any option to have this detected automatically as numeric?

Additional information:
- It is automated, I have this problem on many columns.
- I do not know in advance which columns are numeric.
- I do not know in advance which tables have no data.

Re: How to preserve numeric column types when concatenating tables with empty columns

jthi — Thu, 27 Nov 2025 15:58:33 GMT

You can check if columns are numeric before concatenation and update final result accordingly. Or you could go over character columns after you are done concatenating and change them. I haven't tried this exact method myself (<< fail on conversion), but I think it should work fine

Names Default To Here(1);
dt = New Table("My Table",
	New Column("col1", Character, "Nominal", Set Values({"123", "456", "abc", "789", "", "def"})),
	New Column("col2", Character, "Nominal",Set Values({"123", "456", "789", "", "", ""}))
);

For Each({colname}, dt << Get Column Names("Character", "String"),
	r = Column(dt, colname) << Set Data Type("Numeric", <<Fail On Conversion Error, <<Return Failed Rows);

	If(N Items(r) == 0,
		Column(dt, colname) << Set Modeling Type("Continuous");
	);
);

Re: How to preserve numeric column types when concatenating tables with empty columns

SophieCuvillier — Fri, 28 Nov 2025 10:16:36 GMT

Hello, thank you I didn't now about these functions it solved my issue !