[GRASS5] v.db.updatecol and v.db.addcolumn

[Radim Blazek]

Moritz Lennert wrote:
> On Wed, May 25, 2005 11:49, Radim Blazek said:
> 
>>Moritz Lennert wrote:
>>
>>>Hello,
>>>As I mentioned in a separate mail, I agree with Daniel that using external
> 
> (point-and-click) tools might not be the best way for GRASS attribute
> management.
> 
>>>So, here are two small modules which interface db.execute for specific tasks,
>>>respectively adding a column and updating a column value. Others might follow
>>>according to need.
>>>Any feedback welcome.
>>>Moritz
>>
>>Good, I'll use both.
>>
>>v.db.addcolumn
>>--------------
>>
>>I think that v.db.addcolumn should support the possibility to add more
> 
> columns in one step. It is however dangerous (name - type order for more
> columns) to have column names and typse in 2 separated options. I suggest
> one option columns in format
> 
>>columns="name1 type1[, name2 type2, ...]"
>>
>>the same option is already used in v.in.ascii.
>>
>>Do you think that it is too difficult for users to write
>>
>>columns="newcol integer"
>>
>>instead of
>>
>>colname=newcol coltype=integer
>>
> 
> 
> No I guess it is not too difficult, although I have actually been thinking in
> a different, even simpler direction where the user wouldn't enter the type,
> but chose it from a drop-down menu. Is this realistic or are the available
> types different for every database backend ?

Yes, column types cannot be predefined because depends on database.

> This said, if I implement your suggestion: can this be done in one alter table
> command (and if yes could you show me since I can't seem to find out how), or
> would this be one alter command for each new column (not difficult to code
> either) ?

You have to parse imput and use more commands.

Radim