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Projection mapping, similar to video mapping and spatial augmented reality, is a projection technique [1] [2] used to turn objects, often irregularly shaped, into display surfaces for video projection. The objects may be complex industrial landscapes, such as buildings, small indoor objects, or theatrical stages.
SRIDs are the primary key for the Open Geospatial Consortium (OGC) spatial_ref_sys metadata table for the Simple Features for SQL Specification, Versions 1.1 and 1.2, which is defined as follows: CREATE TABLE SPATIAL_REF_SYS ( SRID INTEGER NOT NULL PRIMARY KEY , AUTH_NAME CHARACTER VARYING ( 256 ), AUTH_SRID INTEGER , SRTEXT CHARACTER VARYING ...
jOOQ Object Oriented Querying, commonly known as jOOQ, is a light database-mapping software library in Java that implements the active record pattern.Its purpose is to be both relational and object oriented by providing a domain-specific language to construct queries from classes generated from a database schema.
In practical terms, if a relation is thought of as a table, then projection can be thought of as picking a subset of its columns. For example, if the attributes are (name, age), then projection of the relation {(Alice, 5), (Bob, 8)} onto attribute list (age) yields {5,8} – we have discarded the names, and only know what ages are present.
It can automatically create the corresponding classes from a database schema, as well as allow manual editing to create a different view by using only a subset of the tables or columns in a table. [13] The mapping is implemented by the DataContext that takes a connection string to the server, and can be used to generate a Table<T> where T is ...
The relational algebra uses set union, set difference, and Cartesian product from set theory, and adds additional constraints to these operators to create new ones.. For set union and set difference, the two relations involved must be union-compatible—that is, the two relations must have the same set of attributes.
creating catalog entries for named queries (views) Graph query language extensions include [48] graph union; projection of graphs computed from the results of pattern matches on multiple input graphs; support for tables (Spark DataFrames) as inputs to queries ("driving tables") views which accept named or projected graphs as parameters.
[citation needed] For this reason, many programmers find themselves more at home with an object-SQL mapping system, even though most object-oriented databases are able to process SQL queries to a limited extent. Other OODBMS provide replication to SQL databases, as a means of addressing the need for ad-hoc queries, while preserving well-known ...