Joining Sheets

Much like in SQL, VisiData lets you join multiple sheets together.

Note

If this concept is unfamiliar, you can read more about joins here and also here.

The sheet-joining three-step

To join two or more sheets in VisiData, you’ll do the following:

1. In the sheets you want to join, mark the shared columns as “keys”
2. In the Sheets Sheet, select the sheets you want to join
3. Press & to open the join-choice prompt, type your desired join type (or press Control-x to open the interactive chooser) and press Enter

VisiData supports seven types of joins:

Join command	SQL equivalent	Description
inner	LEFT INNER JOIN	Keeps only rows which match keys on all sheets
outer	LEFT OUTER JOIN	Keeps all rows from first selected sheet
full	FULL OUTER JOIN	Keeps all rows from all sheets (union)
diff		Keeps only rows NOT in all sheets
append	UNION ALL	Keeps all rows from all sheets (concatenation)
extend		Copies first selected sheet, keeping all rows and sheet type, and extends with columns from other sheets
merge		Merges differences from other sheets into first sheet; keeps all rows from first sheet, updating any False-y values (e.g., False, None, 0, []) with non-False-y values from subsequent sheets, and adds unique rows from subsequent sheets

(Descriptions above come from VisiData’s Quick Reference.)

Practical example

To see an example of joining in action, see the Distinctive Birds chapter.