[ROOT] / doc / toc / ARCQuery / Class / MemberEntityKey
FunctionKeys , QuantileKey , ToString , TryGetP , TryGetPInternal
Can find value for entity which is member of entity being queried.
Works when either:
1) Member key is strongly defined in a schema for the member key (there must exist a PK for the member key).
2) Member key is a EntityMethodKey.
Note: 2) was added on 3 Jan 2022.
It is useful only in more obscure scenarios, because having an EntityMethodKey return an 'Entity' (like 'Customer' or 'Order') is normally superfluous, because that is exactly the purpose of ForeignKey.
If however ForeignKey is not usable in a specific scenario (that is, if it is not able to automatically deduce which foreign entity is desired), this might come in handy.
Example (from AgoRapide documentation): DocFrag contains Attribute which itself is an entity.
This key (MemberEntityKey) then enables queries like 'DocFrag/SELECT Attribute.MethodSignature'.
The key may be chained, that is, it can find value for member of member and so on.
See also ForeignKey.
NOTE: As of Mar 2021 quite new and untested. See TODO about parsing below.
| FunctionKeys | All FunctionKeys chained at end of compound key (but before an eventual QuantileKey). |
| QuantileKey | Eventual final QuantileKey at end of compound key. |
| ToString | The ToString representation is the one relevant when used as key, like in IK or when selecting like 'SELECT {fieldName}'. |
| TryGetP | The outwards facing executor, understanding use of FunctionKeys. |
| TryGetPInternal | The internal executor, containing the specific functionality for how to evaluate the key. |
Generated 2024-04-26 15:10:43.205 UTC