Hi Maris, On 2024-01-15 at 02:10 -08, Maris Nartiss <maris....@gmail.com> wrote... > v.edit tool=catadd/catdel is the thing you are looking for. Delete old > geometry, delete category of new geometry (if there is one), set old > cat value to the new geometry.
Thank you for the suggestion. I don't need cat to be the same. I'm deleting ~100 cats (old vector lines) and replacing with only one new one anyway. More importantly, in my simplified example I neglected to mention that although I want to keep some attributes, I don't want to keep all. There are several old attributes that are no longer relevant for this one manually created line. I was going to create the new line (as below) and then in a for loop: for a in attr1 attr2 attr3 attr4; do # attrs I want to keep or copy # db.select statement to get attr1 value from $old_cat # db.execute sql='UPDATE test set a = $att where cat=$new_cat done Alternatively, if I follow your advice, then I'd need to: for a in attr1 attr2 attr3 attr4; do # attrs I want to delete # db.execute sql='UPDATE test set $attr = NULL where cat=$new_cat done So... is this looping method correct, or is there some SQL statement that will copy attr1,attr2,attrn from row x (defined by an ID or cat) to row y? Thanks, -k. >> I'd like to replace multiple vector lines with ID == 42 with one new >> one, and keep the attributes (date, year, name) from one of the >> replaced/removed lines. >> >> I'm able to create my one new line with: >> >> >> I'm not sure how to copy over the relevant attributes from one of the >> lines (first, last, doesn't matter) that has the relevant ID. >> >> Once I do that, I think I know how to delete the lines I don't want, >> but I'm not sure I'm doing it correct. It seems I have to run two >> commands to delete the lines from both the vectors (when displaying) >> and the database (when querying). I'm doing this: >> >> v.edit map=test tool=delete where="ID == 42" db.execute sql="DELETE >> FROM test WHERE ID == 42" >> >> Can anyone help with the middle step? >> >> Thanks, >> _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user