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Version: 11.2

$.udb(ds).extraKeys()

note

This article is about the extraKeys() function of the DataSourceContainer object.

$.udb(ds).extraKeys()​

Gets the extra key columns of the first data source in the container. Extra keys are columns that are used as keys in a relation to a child or lookup data source, but that are not part of that data source's own key definition.

Returns a Map object, where each entry maps an extra key column name to its alias.

Syntax​

$.udb( *ds* ).extraKeys()

The required ds parameter is a data source selector.

Example​

// combine the data source's own keys with its extra keys to get every column
// that is needed to uniquely identify and relate one of its records
let allKeyCols = new Map([...$.udb('EMP').keys(), ...$.udb('EMP').extraKeys()]);

allKeyCols.forEach((alias, name) => {
    console.log('%s (alias: %s) is required to reference this data source', name, alias);
});