Identify wells without having to query per row of a table

[kinverarity1]

Is your feature request related to a problem? Please describe.

If I have well identifiers scattered across multiple columns, how can I find those wells in a consistent way, that makes it easy to query for new data? e.g.

dh_no	obs_no	unit_no
	ule91
123456
		S-6628-123
	PTA 114	662820331

Describe the solution you'd like

A way to add a new column to the above table by querying only a minimal number of times (i.e. 2-3 times, not once per row). The new column should contain at a minimum a reliable well identifier.