IDataModelManager::CreateMetadataStore method (dbgmodel.h)

Article
02/22/2024

The CreateMetadataStore method creates a key store -- a simplified container of key/value/metadata tuples -- which is used to hold metadata that can be associated with properties and a variety of other values.

A metadata store may have a single parent (which in turn can have a single parent). If a given metadata key is not located in a given store, its parents are checked. Most metadata stores do not have parents. It does, however, provide a way of sharing common metadata easily.

Syntax

HRESULT CreateMetadataStore(
  IKeyStore *parentStore,
  IKeyStore **metadataStore
);

Parameters

parentStore

The parent store for the newly created metadata store. This may be null if there is no parent.

metadataStore

The newly created metadata store will be returned here.

Return value

This method returns HRESULT that indicates success or failure.

Remarks

Sample Code

ComPtr<IDataModelManager> spManager; /* get the data model manager */

// Create an empty key store (the usual case) which will be later filled with metadata.
ComPtr<IKeyStore> spMetadata;
if (SUCCEEDED(spManager->CreateMetadataStore(nullptr, &spMetadata)))
{
    // spMetadata now is an empty store.  You can set key values 
    // like 'PreferredRadix', 'PreferredFormat', 'PreferredLength', etc...
    ComPtr<IKeyStore> spChildMetadata;
    if (SUCCEEDED(spManager->CreateMetadataStore(spMetadata.Get(), &spChildMetadata)))
    {
        // spChildMetadata now is an empty store.  If a key queried from 
        // it does not exist there, it will be queried from spMetadata.
        // This can be useful to override properties on some store without
        // modifying or copying it.
    }
}

Requirements

Requirement	Value
Header	dbgmodel.h