Key - Key value
In order to simplify passing key values to different functions, automatic conversion from string to key is supported by this class. Since a key value is a complex instance, it is structured according to a type definition. Providing key values in a proper internal instance format is rather complicated. Hence, key values can be passed as typed strings in one of the supported string formats (usually CSV with '|' as key component separator). Besides, key values can be provided in ESDF, OIF or XML format.
The key requires a type definition in order to convert key values. The type definition, however, need not to be provided by the application. It will be assigned to the string key, when key conversion is required, e.g. when calling Property::insert(vPrimaryKey) and passing the key as parameter to the function. In this case, the insert() function assigns the proper type definition to the string key.
A key object might be reused in several function calls to any property handle. The type definition for the key will be updated automatically, whenever required.
In order to change string type or set data type additional functions are available in TypedString.
// internal number for person
"12345"
// name key containing name and first name
"Miller|Anton"
// mae key with several first names
"Miller|(Anton|Paul)"
// employee key consisting of person key and employee number
"{Miller|Anton}|111"