SpatiaLite – WITH, view or sub-query?

Does SQLite support subquery?

In SQLite, a subquery is a query within a query. You can create subqueries within your SQL statements. These subqueries can reside in the WHERE clause, the FROM clause, or the SELECT clause.

What is SpatiaLite used for?

SpatiaLite is an open source library intended to extend the SQLite core to support fully fledged Spatial SQL capabilities. SQLite is intrinsically simple and lightweight: a single lightweight library implementing the full SQL engine. standard SQL implementation: almost complete SQL-92.

Does subquery reduce performance?

A Sub-Query Does Not Hurt Performance.
 

What are the disadvantages of subquery?

Advantages and Disadvantages of Subqueries



A disadvantage is that you cannot modify a table and select from the same table within a subquery in the same SQL statement. Subqueries also can take longer to execute than a join because of how the database optimizer processes them.

How do you run a Spatialite GUI?

Start Spatialite and load a database

1. Open the Spatialite GUI by selecting Geospatial->Databases->Spatialite GUI.
2. Select File->Connecting an existing SQLite DB.
3. Browse to the /home/user/data/spatialite directory and choose trento.
4. Right click on the MunicipalHallsView table and select “Show Columns”

Is SQLite a spatial database?

SpatiaLite is a spatial extension to SQLite, providing vector geodatabase functionality. It is similar to PostGIS, Oracle Spatial, and SQL Server with spatial extensions, although SQLite/SpatiaLite aren’t based on client-server architecture: they adopt a simpler personal architecture.

How do I create a Spatialite database?

How to create a spatial database

1. Open QGIS and the exploration panel. If the panel Browse is missing, click View | Panels , and click Browse .
2. Create a new database Spatiality by clicking SpatiaLite and selecting. Create a database …
3. Select the directory of your choice and name the new database, for example BaseTest.

How to create a subquery in SQLite?

Introduction to SQLite subquery



You must use a pair of parentheses to enclose a subquery. Note that you can nest a subquery inside another subquery with a certain depth. Typically, a subquery returns a single row as an atomic value, though it may return multiple rows for comparing values with the IN operator.

Which is not supported by SQLite?

The SQLite database engine does not support a number of schema operations that are supported by the majority of other relational databases.
 

What are the limitations of SQLite?

An SQLite database is limited in size to 281 terabytes (2⁴⁸ bytes, 256 tibibytes). And even if it could handle larger databases, SQLite stores the entire database in a single disk file and many filesystems limit the maximum size of files to something less than this.