[GRASS-user] RE: Problem querying layers other than '1' in gi s.m

[Patton, Eric]

Dylan wrote:
>Eric, the way that i usually approach this type of problem in GRASS is
>as follows:

>1. store my attribute data in a RDBMS such as mysql, postgresql, sqlite,
>etc.
>2. create some vector data with at least two columns: 'cat' and 'id'
>'cat' is used by v.db.connect to associate a row with a vector feature
>'id' is used to associate other attribute data with a row

>3. create a new, composite  table (from two existing tables 'vector' 
>and 'data') with something like:
>create table new_table as 
>select vector.cat, vector.id, data.time, data.temp
>from vector, data
>where vector.id = data.id ;

>4. then hookup new_table to the original vector file with v.db.connect

>make sense? 

Thanks, Dylan. Your SQL code worked and I now have a single table that
combines the fields of interest from both tables. However....

Any attempt to edit the field names or types result in the error "Error
editing field. Message from database engine: near ".": syntax error". I
should note that as a result of the SQL join of the two tables, the field
names are really long now:

db.columns table=Rumbolt_Video_Benthos_Corrected_UTC_NR
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.ID
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Station_ID
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Depth_m
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Latitude
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Longitude
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Julian_Day
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.UTM_time
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Sediment_type
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Description
Rumbolt_Video_Benthos_Uncorrected_UTC_NR.Uncorrected_UTC
All_UTCs_clock_corrected_NR.ID
All_UTCs_clock_corrected_NR.Timestamp

Could the error I'm getting be caused by the length of the new field names? 

~ Eric.

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341