v.db.connect(1)

1v.db.connect(1)               Grass User's Manual              v.db.connect(1)
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NAME

6       v.db.connect  - Prints/sets DB connection for a vector map to attribute
7       table
8

KEYWORDS

10       vector, database, attribute table
11

SYNOPSIS

13       v.db.connect
14       v.db.connect help
15       v.db.connect  [-pgcod]  map=name   [driver=string]    [database=string]
16       [table=string]   [key=string]   [layer=integer]
17
18   Flags:
19       -p  Print current map connection parameters and exit
20
21       -g  Print  current  map  connection  parameters  and exit (shell script
22           style) format:  layer[/layer name] table key database driver
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24       -c  Print types/names of table columns for specified layer and exit
25
26       -o  Overwrite connection parameter for certain layer
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28       -d  Delete connection for certain layer (not the table)
29
30   Parameters:
31       map=name
32           Name of input vector map
33
34       driver=string
35           Driver name Options: dbf,mysql,ogr,pg,sqlite,mesql,odbc
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37       database=string
38           Database name
39
40       table=string
41           Table name
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43       key=string
44           Key name (must refer to an integer column) Default: cat
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46       layer=integer
47           Layer number Default: 1
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DESCRIPTION

50       v.db.connect prints or sets database connection for a vector map.
51

NOTE

53       If parameters for database connection are already set with  db.connect,
54       they  are  taken  as default values and do not need to be spcified each
55       time.
56
57       Attention: Removing a vector map will also delete all tables linked  to
58       it!  If  you use v.db.connect to link further tables to your map, it is
59       advisable to make a copy from those tables first and connect the copied
60       tables to the vector map (see also v.overlay).
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EXAMPLE

63       Print database connection
64
65       v.db.connect -p map=vectormap
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67
68       Print column types and names of table linked to vector map
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70       v.db.connect -c map=vectormap
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72
73   Connect vector map to database (DBF driver)
74       Connect vector map to DBF table without or with variables
75       Using default DB connection:
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77       v.db.connect map=vectormap table=table
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79
80       Using hardcoded path to DBF directory (not recommended):
81
82       v.db.connect   map=vectormap   table=table   database=/home/user/grass‐
83       data/spearfish60/PERMANENT/dbf
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85
86       Using variable as DBF directory definition, single quotes must be used:
87
88       v.db.connect   map=vectormap   table=table   database='$GISDBASE/$LOCA‐
89       TION_NAME/$MAPSET/dbf/'
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91
92       Connect vector map layer 2 and key ID to database with variables
93       (note:  if  needed, single quotes must be used for the database parame‐
94       ter)
95
96       v.db.connect map=vectormap table=table layer=2 key=ID
97
98
99   Connect vector map to database (MySQL driver)
100
101       # note: connection which requires password
102       db.connect driver=mysql database="host=dbserver.foo.org,dbname=my_data‐
103       base"
104       db.login user=joshua [password=xxx]
105       # ... or enter password interactively.
106       db.tables -p
107       # connect external table to layer 2:
108       v.db.connect map=my_map table=my_mysql_table key=baz layer=2
109       v.db.connect -p my_map
110
111
112   Connect vector map to database (PostgreSQL driver)
113
114       # note: connection without password being asked
115       v.db.connect map=vectormap table=table layer=1 key=oid driver=pg \
116                    database="host=myserver.itc.it,dbname=mydb,user=name" \
117                    table=mytable key=id
118
119
120   Store geometry in GRASS but attributes in PostgreSQL
121       This  example  illustrated  a  mixed  data storage with possibility top
122       update attributes in external PostgreSQL database:
123       # Check current settings for attribute storage:
124       db.connect -p
125       # Import table from PostgreSQL to new map
126       # (NOTE: output map name needs to be different from table name in
127       #        case that GRASS is connected to PostgreSQL):
128       v.in.db driver=pg database="host=localhost,dbname=meteo" \
129               table=mytable x=lon y=lat key=cat out=mytable
130       v.db.connect map=mytable -p
131       # Cancel table connection between map and attribute table:
132       v.db.connect map=mytable -d
133       v.db.connect map=mytable -p
134       # Drop table which was replicated due to import:
135       db.tables -p
136       echo "DROP TABLE mytable" | db.execute
137       db.tables -p
138       # reconnect map to table in PostgreSQL:
139       v.db.connect      map=mytable      driver=pg      database="host=local‐
140       host,dbname=meteo" \
141               table=mytable key=cat
142       # Now the geometry is stored in GRASS while the attributes are stored
143       # in PostgreSQL.
144        An alternative is to create a "view" of only ID, x, y [,z] columns and
145       to use v.in.db on this view, then connect the  original  table  to  the
146       geometry. This will be faster if the original table is very large.
147
148   Store geometry in GRASS but attributes in PostGIS
149       This  example  illustrated  a  mixed  data storage with possibility top
150       update attributes in external PostGIS database:
151       # Check current settings for attribute storage:
152       db.connect -p
153       # Import table from PostGIS to new map
154       # (NOTE: output map name needs to be different from table name in
155       #        case that GRASS is connected to PostGIS):
156       v.in.db driver=pg database="host=localhost,dbname=meteo" \
157               table=mytable x="x(geom)" y="y(geom)" key=cat out=mytable
158       v.db.connect map=mytable -p
159       # Cancel table connection between map and attribute table:
160       v.db.connect map=mytable -d
161       v.db.connect map=mytable -p
162       # Drop table which was replicated due to import:
163       db.tables -p
164       echo "DROP TABLE mytable" | db.execute
165       db.tables -p
166       # reconnect map to table in PostGIS:
167       v.db.connect      map=mytable      driver=pg      database="host=local‐
168       host,dbname=meteo" \
169               table=mytable key=cat
170       # Now the geometry is stored in GRASS while the attributes are stored
171       # in PostGIS.
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AUTHOR

179       Radim Blazek, ITC-Irst, Trento, Italy
180
181       Last changed: $Date: 2007/05/02 13:27:24 $
182
183       Full index
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186
187GRASS 6.2.2                                                    v.db.connect(1)