What do you need to know about SpatiaLite?

What do you need to know about SpatiaLite?

SpatiaLite sweetens this little database by allowing you to store geometries and query them with spatial functions similar to what you would find in PostgreSQL/PostGIS, Microsoft SQL Server 2008, MySQL, IBM DBII, Oracle Locator/Spatial.

What is the purpose of the spatial index?

The spatial index is a data structure between the operation algorithm and the actual spatial object. Th rough searching in the spatial index, quickly calculation that needs to be accurately calculated, and improve the query.

Is there a same license for SpatiaLite as SQLite?

Spatial Transformation support using Proj.4 that hmm even SQL Server 2008 lacks As far as licensing goes, SpatiaLite does not have the same License as SQLite. It is under 3 licenses Mozilla Public and GPLv3 In this little exercise, we shall get you up and running quickly with this cute cute database engine.

Which is the latest version of SpatiaLite for Windows?

You can also use the latest Spatialite-gis minimalist, which has viewer and shapefile importer packaged in. Latest version is 1.0 Alpha and binaries available for Windows, Linux, and Mac OSX. SpatiaLite provider code for sharmap version 0.9 written by Bill Dollins.

Which is the easiest way to load shape data into SpatiaLite?

The easiest data to load into SpatiaLite is to use the ESRI shape data loader packaged with the SpatiaLite gui. From the SpatiaLite gui –> File -> Load Shape file and browse for TOWNS_POLY.shp and type in 26986 for SRID. Type in the_geom for field name.

How to run a SQL script in SpatiaLite?

Launch the GUI. From menu choose –> files -> Create a new SQLiteDb. Call the file boston.sqlite. Choose the little icon with tooltip “Execute SQL Script” and choose init_spatialite-2.2.sql. Choose Latin if prompted for encoding. Right mouse-click on the database and hit refresh and you should see three tables.

One additional step is required for using SpatiaLite: create the geometry_columns and spatial_ref_sys metadata tables. This is done by calling SpatiaLite’s InitSpatialMetaData function: Note that this operation may take some time the first time it is executed for a database. When InitSpatialMetaData is executed again it will report an error:

How to create a lake table in SpatiaLite?

Setting management to True indicates that the AddGeometryColumn and DiscardGeometryColumn management functions will be used for the creation and removal of the geometry column. This is required with SpatiaLite. We can now create the lake table in the gis.db database:

Why are there no binary literals in SpatiaLite?

I think may be due to Sqlite thinking that the bracked value in the second statement is a string literal and not being able to transform it into a blob/binary literal. Does anyone have any solutions either within spatialite itself or using a third party library in python or something?

Which is listener is responsible for loading SpatiaLite?

The listener is responsible for loading the SpatiaLite extension, which is a necessary operation for using SpatiaLite through SQL. At this point you can test that you are able to connect to the database: You can also check that the gis.db SQLite database file was created on the file system.

What does an R-tree do in SpatiaLite?

An R-Tree basically stores the bounding box of the geometry as the index. For large complex geometries unfortunately, this is not too terribly useful. SpatiaLite 3.6+ as mentioned has R-Tree indexes The most common queries we will be doing on this query are spatial queries and queries by the town field.

How are spatial indexes created in SQL Server?

Creates a spatial index on a specified table and column in SQL Server. An index can be created before there is data in the table. Indexes can be created on tables or views in another database by specifying a qualified database name. Spatial indexes require the table to have a clustered primary key.

How to load Esri shape data into SpatiaLite?

Most if not all MassGIS data is in this particular projection. The easiest data to load into SpatiaLite is to use the ESRI shape data loader packaged with the SpatiaLite gui. From the SpatiaLite gui –> File -> Load Shape file and browse for TOWNS_POLY.shp and type in 26986 for SRID. Type in the_geom for field name.

How to ignore an error in SpatiaLite database?

This is done by calling SpatiaLite’s InitSpatialMetaData function: Note that this operation may take some time the first time it is executed for a database. When InitSpatialMetaData is executed again it will report an error: You can safely ignore that error.

Is there a SQLAlchemy session associated with Spatialite?

There’s nothing specific to SpatiaLite here. When using the SQLAlchemy ORM the ORM interacts with the database through a Session. The session is associated with our SpatiaLite Engine. Again, there’s nothing specific to SpatiaLite here.

Can you use geoalchemy 2 with Spatialite database?

But GeoAlchemy 2 also supports SpatiaLite, the spatial extension to SQLite. This tutorial describes how to use GeoAlchemy 2 with SpatiaLite. It’s based on the ORM Tutorial, which you may want to read first. Just like when using PostGIS connecting to a SpatiaLite database requires an Engine.

Which is the closest model to PostGIS SpatiaLite?

In terms of the model it uses, it seems closest in syntax to PostGIS and in fact modeled after PostGIS and also piggy-backs on GEOS and Proj.4 like PostGIS.

How do you build spatial index in Excel?

In the tree view that shows the tables, expand towns and right mouse click on the the_geom field and then choose Build Spatial Index. You will see the little icon change on the column once that is done.

Which is the latest version of SpatiaLite driver?

The latest binary distributions of QuantumGIS (as of this writing QGIS 1.4+) now have the SpatiaLite driver built in. You can also use the latest Spatialite-gis minimalist, which has viewer and shapefile importer packaged in. Latest version is 1.0 Alpha and binaries available for Windows, Linux, and Mac OSX.