Composite description views enable access to appropriate individual descriptions or sets of descriptions in a specific language or dialect. There are two sets of composite description views.  Views in the first of these sets are designed to facilitate selecting descriptions associated with one or more identified concepts. Views in the other set are designed to enable searching descriptions to find concepts.

Views that Facilitate Selecting Concept Descriptions

For each snapshot view the SNOMED CT example database includes four views designed for selecting specific sets of descriptions for one or more specified concepts. The characteristics of each of these views are shown in  Table 4.8.2-1 and a general template for the SQL definitions of these views is shown in  Template 4.8.2-1. To create each of the views named in the table, the placeholders for {typeId} and {acceptabilityId} need to be replaced with values in the Specific Settings column of the table. 

Example 4.8.2-1 demonstrates the use of these views to show all the active descriptions of a specified concept that are acceptable or preferred according to the language reference set referenced by the configuration file.

Table 4.8.2-1: Composite Description Views for Selecting Concept Descriptions

Template 4.8.2-1: Description Selection Composite View Template

CREATE VIEW `snap_{name}` AS
(SELECT `d`.* FROM `snap_description` `d`
    JOIN `snap_refset_Language` `rs` ON `d`.`id` = `rs`.`referencedComponentId`
    JOIN `config_settings` `cfg` ON `rs`.`refSetId` = `cfg`.`languageId` 
    WHERE `d`.`active` = 1 AND `d`.`typeId` {typeId}
    AND `rs`.`active` = 1 AND `rs`.`acceptabilityId` {acceptabilityId}
    AND `cfg`.`id`=0);

Example 4.8.2-1: Selecting Description Data for a Concept

Select conceptId,'FSN',id,term from snap_fsn where conceptId=95570007
UNION
Select conceptId,'Pref',id,term from snap_pref where conceptId=95570007
UNION
Select conceptId,'Syn',id,term from snap_syn where conceptId=95570007;

Views that Facilitate Searching for Concepts

For each snapshot view the SNOMED CT example database includes two views that are designed to facilitate searches for concepts associated with terms that match specified criteria. These views require both the description and the associated concept to be active in the chosen snapshot. This avoids the need to filter out inactive concepts from the search results³ . The specific characteristics of these views is shown in  Table 4.8.2-2 and a general template for the SQL definitions of these views is shown in  Template 4.8.2-2. To create the each of the views named in the table, the placeholder for {typeId} needs to be replaced with values in the Specific Settings column of the table. 

Example 4.8.2-2 show a query that searches the snap_syn_search_active view using MySQL's boolean full text search. This search method requires all the words preceded by + (plus) to be included and excludes all words preceded by - (minus). The results are shown together with the fully specified name of the concept (looked up using the snap_fsn view).  Although this is not a user-friendly way to specify a searches, the example SQL code illustrates the technical power of this search technique. Other search techniques can also be applied to the search views and additional options for enhancing searches are discussed in  4.9.4. Search Procedures.

Table 4.8.2-2: Composite Description Views that Facilitate Searching for Concepts

Template 4.8.2-2: Description Search Composite View Template

CREATE VIEW `snap_syn_search_active` AS
(SELECT `d`.*,`rs`.`acceptabilityId` FROM `snap_description` `d`
    JOIN `snap_refset_Language` `rs` ON `d`.`id` = `rs`.`referencedComponentId`
    JOIN `snap_concept` `c` ON `c`.`id` = `d`.`conceptId`
    JOIN `config_settings` `cfg` ON `rs`.`refSetId` = `cfg`.`languageId`
    WHERE `d`.`active` = 1 AND `d`.`typeId` {typeId}
    AND `rs`.`active` = 1
    AND `c`.`active` = 1
    AND `cfg`.`id`=0);

Usage Example

Example 4.8.2-2: Searching Terms to Find Concepts

SELECT `s`.`conceptId`,`s`.`term` 'matching term',`f`.`term` `FSN` FROM `snap_syn_search_active` `s`
	JOIN `snap_fsn` `f` ON `f`.`conceptId`=`s`.`conceptId`
    WHERE MATCH (`s`.`term`)
			AGAINST ('+acute +anterior +myocardial +infarction -ecg -old -ekg' IN BOOLEAN MODE) ORDER BY length(`f`.`term`),length(`s`.`term`);