NOMBRE
d.site.pg - Muestra los sites seleccionados por una consulta
a base de datos.
(GRASS-RDBMS Interface Display Program)
USO
d.site.pg
d.site.pg help
d.site.pg tab=name coords=X-column,Y-column
where=name [cats=name] [map=name] [plot=color,icon,size]
[join=tab,tabkey,pkey]
ALTERNATIVO
d.site.pg -s help
d.site.pg -s sql=filename [map=name][plot=color,icon,size]
DESCRIPCION
Los sites devueltos de la base de datos se muestran como iconos cuyas características
(color, tipo de icono y tamaño) se establecen en el parámetro
plot=. Si se especifica el parámetro map= se creará
una nueva lista de sitios cuya categoría será la que se invocó
con el parámetro cats=
Parametros:
-
tab=databasetablename
-
Tabla que contiene dos columnas con las coordenadas X e Y
-
coordx=databasecolumnname coordy=databasecolumnname
-
Columnas que contienen las coordenadas X e Y
-
where=SQLwhereclause
-
sentencia SQL para establecer los criterios de búsqueda de la consulta:
For example, if you want to select only those records from the table well
where the value for depth is either 58 or 75 the following could be entered:
well.depth = 58 or well.depth = 75
To select all wells in an area where the value for well is between
50 and 120:
well.depth > 50 and well.depth < 120
To select all wells of depth greater than 75 where the value for
owner is not equal to SMITH:
well.depth > 75 and well.owner != "SMITH"
If the database column used as the selection criteria is a character
field then the associated value must be placed in double quotes. To determine
the data types associated with columns in the currently selected database
use the g.column.pg command with the -v flag.
In addition to the operators presented in the examples above a range
of relational operators including and, or, etc. are supported. There may
be some differences in the relational operators which are supported with
different database drivers.
The examples presented above were created using the command line parser.
If d.site.pg is being called from a shell script remember to escape
quoted strings. The follwing example presents a component of a shell script
used to join two tables and display vector features where the database
column ad.pgo is set to "NONE".
d.site.pg tab=well coords=utme,utmy
where=ad.info='"NONE"'map=$1 plot=green,plus,2 join=rds2,rds2.cat2,well.cat
Queries which are more complex than these are best implemented using
the -s flag and a prepared SQL file.
-
map=list
-
Name of sites list to output
-
plot=color,icon,size
-
Colors: red, orange, yellow, green, blue, indigo, violet, magenta, brown,
gray, white, black
-
Icon: diamond, box, plus, x
-
Size: 1-9
-
Default: gray, x, 3
-
join=tab,tabkey,pkey
-
Tab is the table used to develop the current SQL query. Tabkey is the database
column used to relate.pgormation in this table with data in the table linked
to the GRASS category file. Pkey is the associated column in the table
linked to the GRASS category file which is related to tabkey in the current
table.
For instance, assume that well is a table containing X,Y coordinate values
and that wellowners is a table containing ownership.pgormation associated
with well logs. To base a query on site location which would return attribute
data on ownership and locational.pgormation in the table well the following
join would be needed on the command line:
tab = well
join=wellowners,wellowners.wellid,well.wellid
The column wellid is common to both the well and the wellowners
table. Because of this attribute data from both tables will be returned
if the coordinates registered by the mouse return a record from the table
well within a radius specified by the distance parameter on the command
line. Specifying these conditions would insure that all rows from table
roads which satisfy the query criteria would be matched with the corresponding
rows in table main, which are then related to the spatial features in the
GRASS data layer via the GRASS category values.
Esta sintaxis sólo resulta adecuada si se está trabajando
con consultas simples, para llevar a cabo consultas m complejas es más
eficiente el modo alternativo (opción -s).
ALTERNATE COMMAND LINE USAGE
Flag:
-
-s
-
La consulta se hace mediante una orden SQL almacenada en un fichero.
Parametros:
-
sql=filename
-
Fichero SQL especificando los criterios de selección
-
map=list
-
Nombre del fichero de sites que va a producirse
-
plot=color,icon,size
-
Colores: red, orange, yellow, green, blue, indigo, violet, magenta, brown,
gray, white, black
-
Iconos: diamond, box, plus, x
-
Tamaños: 1-9
-
Por defecto: gray, x, 3
El fichero SQL contiene una orden SELECT que debe solicitar en primer
lugar las columnas que contengan las coordenadas X e Y de los registros
que cumplan las condiciones más aquellas otras que se deseen. En
el fichero resultante
Ejemplo:
select utm.utme, utm.utmn where utm.mlra="116A" and utm.hydunit=11110103
and utm.utme > 0 and utm.utmn > 0 sort by utme, utmn
NOTA
Requiere Postgres como motor de búsqueda
VER
g.column.pg, g.select.pg,
g.stats.pg, g.table.pg,
d.rast.pg, d.vect.pg,
d.what.r.pg, d.what.s.pg,
d.what.v.pg, r.reclass.pg,
r.rescale.pg, v.reclass.pg
AUTOR
Original Informix SQL-tools: James A. Farley, Wang Song, and W. Fredrick
Limp University of Arkansas, CAST
Postgres modifications: Janne Soimasuo, Faculty of Forestry, University
of Joensuu, Finland.
Updated to GRASS 5 by Alex Shevlakov (sixote@yahoo.com)