On 19/10/10 15:23, Micha Silver wrote:
Moritz Lennert wrote:
On 13/10/10 22:23, Micha Silver wrote:
One line from the v.db.join script uses grep and cut to get the column
names and the next line gets the column types like so:
db.describe -c bike_rides2 | grep '^Column' | cut -d ':' -f 3
INTEGER
CHARACTER
INTEGER
CHARACTER
CHARACTER
CHARACTER
CHARACTER
So the column size is actually ignored.
Next, in the script the above output is used by v.db.addcol to create
the new columns in the joined vector. So all new character columns are
created as a single char and the actual length is never used.
Questions:
Is the db.describe output the same for all db drivers?
Any suggestions how to fix this as a script?
Why not use an SQL join, i.e. something like the following ?
1) CREATE TABLE temp AS (SELECT * FROM $maptable JOIN $otable ON
$column=$ocolumn)
2) rename table $maptable to something else
3) rename table temp to $maptable
4) if this works, remove the original $maptable
Interesting. So your suggestion is to run the above sql commands thru
db.execute to create a new attribute table for an existing vector?
Yes. You could put them all into a temporary text file then send this
file as one transaction to db.execute.
Moritz
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