Example: Function Mapping Definition with Scalar Subquery (SSQ) Substitution - Advanced SQL Engine - Teradata Database

SQL Data Definition Language Syntax and Examples

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Published
January 2021
Language
English (United States)
Last Update
2021-01-22
dita:mapPath
ncd1596241368722.ditamap
dita:ditavalPath
hoy1596145193032.ditaval
dita:id
B035-1144
lifecycle
previous
Product Category
Teradata Vantage™

The function mapping definition sessionize_fm specifies a scalar subquery for the TIMEOUT column value:

SELECT timeout FROM ssqtbl WHERE username='John'

If TIMEOUT is not specified during function processing, the column value is resolved by processing the scalar subquery.

CREATE FUNCTION MAPPING sessionize_fm FOR sessionize SERVER coprocessor
USING
InputTable IN TABLE,
ModelTable IN TABLE,
ClusterTable OUT TABLE,
TIMECOLUMN,
TIMEOUT(SELECT timeout FROM ssqtbl WHERE username='John'),
CLICKLAG,
EMITNULL;