RONCC
/
Geografic-Information-System


			
				
					
						
						
							12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697
							<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>GRASS-SQLite driver</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link rel="stylesheet" href="grassdocs.css" type="text/css">
</head>

<body bgcolor="white">

<img src="grass_logo.png" alt="GRASS logo"><hr align=center size=6 noshade>

<!-- meta page description: SQLite driver -->
<h1>SQLite driver in GRASS</h1>

<h2>Creating a SQLite database</h2>

The SQLite driver is the default DBMI backend.
GRASS is automatically creating the SQLite database if it is not yet
existing when the first table is created in the SQLite database. It
is sufficient to define the connection (see next step).

<h2>Connecting GRASS to SQLite</h2>

The database name 'sqlite.db' is at user's choice.
Also the file storage location can be freely chosen. If the database
does not exist, it will be automatically created when database content
is created:

<div class="code"><pre>
# example for storing DB in mapset directory (keep single quotes):
db.connect driver=sqlite database='$GISDBASE/$LOCATION_NAME/$MAPSET/sqlite.db'
db.connect -p
</pre></div>

<h2>Supported SQL commands</h2>

All SQL commands supported by SQLite (for limitations, see
SQLite help page:
<a href="http://www.sqlite.org/lang.html">SQL As Understood By SQLite</a> and
<a href="http://www.sqlite.org/omitted.html">Unsupported SQL</a>).

<h2>Operators available in conditions</h2>

All SQL operators supported by SQLite.

<h2>Browsing table data in DB</h2>

A convenient SQLite front-end is <a href="http://sqlitebrowser.sourceforge.net/">sqlitebrowser</a>.
To open a DB file stored within the current mapset,
the following way is suggested (corresponds to above database connection):

<div class="code"><pre>
eval `g.gisenv`
# use double quotes:
sqlitebrowser "$GISDBASE/$LOCATION_NAME/$MAPSET"/sqlite.db
</pre></div>

<!-- doesnt work yet, why?:
  ah, pending patch: http://www.sqlite.org/cvstrac/tktview?tn=1476

<h2>Adding an unique ID column</h2>

Import vector module require an unique ID column which can
be generated as follows for a SQLite table:

<div class="code"><pre>
echo "
 ALTER TABLE mytable ADD ID integer;
 CREATE SEQUENCE mytable_seq;
 UPDATE mytabe SET ID = nextval('mytable_seq');
 DROP SEQUENCE mytable_seq;
" | db.execute
</pre></div>
-->

<h2>SEE ALSO</h2>

<em>
  <a href="db.connect.html">db.connect</a>,
  <a href="db.execute.html">db.execute</a>,
  <a href="db.select.html">db.select</a>
  <br><br>
  <a href="sql.html">SQL support in GRASS GIS</a>
  <br><br>
  <a href="http://www.sqlite.org">SQLite web site</a>,
  <a href="http://www.sqlite.org/quickstart.html">SQLite manual</a>,
  <a href="http://www.sqlite.org/cvstrac/wiki?p=ManagementTools">sqlite - Management Tools</a>
</em>

<p>
<i>Last changed: $Date$</i>
<hr>
<br><a href=index.html>Help Index</a>
</body>
</html>