DESCRIPTION
db.select prints result of selection from database based on
SQL statement read from input file or from standard input to standard
output.
NOTE
If parameters for database connection are already set with
db.connect, they are taken as
default values and do not need to be specified each time. Output will
be displayed to standard output or can be directed to a file
(option output).
EXAMPLES
Basic usage
db.select sql="select * from roads"
or
echo "select * from roads" | db.select input=-
or
or
cat file.sql | db.select input=-
Select all from table roads:
db.select -c driver=odbc database=mydb table=hospitals \
input=file.sql output=result.csv
Select some string attribute, exclude others:
db.select sql="SELECT * FROM archsites WHERE str1 <> 'No Name'"
Select some string attribute with ZERO length:
db.select sql="SELECT * FROM archsites WHERE str1 IS NULL"
Select coordinates from PostGIS table:
db.select sql="SELECT x(geo),y(geo) FROM localizzazione"
Execute multiple SQL statements
cat file.sql
SELECT * FROM busstopsall WHERE cat = 1
SELECT cat FROM busstopsall WHERE cat > 4 AND cat < 8
db.select input=file.sql
Count number of cases falling into same position
When multiple observation have the spatial coordinates, they can still
be counted (if needed, coordinates can be uploaded to the attribute
table by v.to.db:
db.select sql="SELECT long,lat,site_id,department,obs,COUNT(long) as count_cases \
FROM diseases GROUP BY long,lat"
SEE ALSO
db.connect,
db.describe,
db.drivers,
db.droptable,
db.execute,
db.login,
db.tables
GRASS SQL interface
AUTHORS
Original author unknown (probably CERL)
Modifications by Radim Blazek, ITC-Irst, Trento, Italy
Support for multiple statements by Martin Landa, Czech Technical University in Prague
Last changed: $Date$