Flags:

-c

Do not include column names in output

-d

Describe query only (don’t run it)

-v

Vertical output (instead of horizontal)

-t

Only test query, do not execute

--overwrite

Allow output files to overwrite existing files

--help

Print usage summary

--verbose

Verbose module output

--quiet

Quiet module output

--ui

Force launching GUI dialog

Parameters:

sql=sql_query

SQL SELECT statement
Example: select * from towns where population > 10000

input=name

Name of file containing SQL select statement(s)
’-’ for standard input

table=name

Name of table to query

driver=name

Name of database driver
Options: dbf, mysql, odbc, ogr, pg, sqlite
Default: sqlite

database=name

Name of database
Default: $GISDBASE/$LOCATION_NAME/$MAPSET/sqlite/sqlite.db

separator=character

Field separator
Special characters: pipe, comma, space, tab, newline
Default: pipe

vertical_separator=character

Vertical record separator (requires -v flag)
Special characters: pipe, comma, space, tab, newline

null_value=string

String representing NULL value

output=name

Name for output file (if omitted or "-" output to stdout)

Basic usage

db.select sql="select * from roads"

or

echo "select * from roads" | db.select input=-

or

db.select input=file.sql

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"