Hi,
I'm using MySQL 5.7, and it looks like a column with multiple indexes is displayed multiple times when using columnInfo('table_name').
I've seen this caused problems in directus/directus#6204.

I've been looking at the source code of columnInfo() and tested it on a MySQL instance, and found that the issue comes from the table INFORMATION_SCHEMA.KEY_COLUMN_USAGE and the LEFT JOIN done on it, duplicating the rows from INFORMATION_SCHEMA.COLUMNS (for MySQL).

Only the columnInfo('table_name', 'column_name') function seems to work properly (not showing any duplicate entries), since it only returns the first column found.
Using a GROUP BY c.TABLE_NAME, c.COLUMN_NAME on the query looks like it prevents the duplicate indexes to show up, but there might be loss of information in that case?