Database query

Database Query
Database query is to retrieve the attribute data without altering the existing data. The function can be performed by simply clicking on the feature or by means of a conditional statement for complex queries.

Database query founded on neighborhood relationships (within polygon, associated to object, etc.) is a fundamental requirement for data exploration. Our group has begun using a tool developed within one of our projects, MapMosaic, for spatial queries.

Database query language
Information retrieval query language
Relation
Relational database
Relational database management system
The Third Manifesto (TTM)
TransRelational model
Tuple-versioning ...

A database query language and report writer to allow users to interactively interrogate the database, analyze its data and update it according to the users privileges on data. It also controls the security of the database.

Q
Query or Database Query: The retrieval and display of data from a database about one or more features, such as a parcel, its size, owner, value and location or address.

For example, a simple database query to populate a common business form delivers a few rows of data from the DBMS while a map draw will require a database query that returns hundreds, and even thousands of records.

This tutorial will explain how to get the extent of your GIS data from a PostgreSQL database query. You must have the SELECT privilege to a PostgreSQL database with PostGIS functions as well as a table containing your geometry or GIS data.

It is possible to select features to display by using a database query, but this only selects those features and displays them in the selection color. Once the selected set is cleared, all features will once again be displayed in the original symbol.

SQL (Structured query language) - The standard database query language for relational database systems. See also Data definition language and Data manipulation language.
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Common components of GIS analysis include database query and selection, database linking, buffering, topological overlay, clipping, dissolving, etc. This work is mainly done by GIS processing software.

starting point coordinates, X,Y or X,Y,Z end: line/boundary end point coordinates, X,Y or X,Y,Z sides: categories of areas on the left and right side of the boundary, 'qlayer' is used for area category query: result of a database query ...

See also: Database, Query, Model, GIS, Access