Qualifier Domains

Qualifier domains contain information solely to clarify the mapping. A mapping might be ambiguous unless this additional information is defined. For example, a domain value map that defines a city name mapping could have multiple mappings from KN to Kensington because Kensington is a city in both Canada and the USA. Therefore, this mapping requires a qualifier (USA or Canada) to indicate which mapping to use. An example of this is shown in Table 45-2.

Table 45-2 Qualifier Support Example

Country (Qualifier)	CityCode	CityName
`USA`	`BO`	`Boston`
`USA`	`BELG_NC`	`Belgrade`
`USA`	`BELG_MN_Streams`	`Belgrade`
`USA`	`NP`	`Northport`
`USA`	`KN`	`Kensington`
`Canada`	`KN`	`Kensington`

A domain value map can contain multiple qualifier domains. For example, as shown in Table 45-3, the mappings are also qualified with a state name.

Table 45-3 Multiple Qualifier Support Example

Country (Qualifier)	State (Qualifier)	CityCode	CityName
`USA`	`Massachusetts`	`BO`	`Boston`
`USA`	`North` `Carolina`	`BELG`	`Belgrade`
`USA`	`Minnesota`	`BELG`	`Belgrade`
`USA`	`Alabama`	`NP`	`Northport`
`USA`	`Kansas`	`KN`	`Kensington`
`Canada`	`Prince` `Edward` `Island`	`KN`	`Kensington`

Qualifiers are used only to qualify the mappings. Therefore, the qualifier values cannot be looked up.