NAME

       db.select  - Selects data from attribute table.
       Performs SQL query statement(s).

KEYWORDS

       database, attribute table, SQL

SYNOPSIS

       db.select
       db.select --help
       db.select   [-cdvt]    [sql=sql_query]     [input=name]     [table=name]     [driver=name]
       [database=name]            [separator=character]            [vertical_separator=character]
       [null_value=string]    [output=name]    [--overwrite]   [--help]   [--verbose]   [--quiet]
       [--ui]

   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)

DESCRIPTION

       db.select prints result of selection from database based on SQL statement read from  input
       file or from standard input to standard output. Each individual query has to be written on
       one single line and different queries have to be written on separate lines.

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
       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"

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

SOURCE CODE

       Available at: db.select source code (history)

       Accessed: Thursday Aug 01 11:29:34 2024

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       © 2003-2024 GRASS Development Team, GRASS GIS 8.4.0 Reference Manual