private bool TryExecuteQuery(TranslationResult translationResult, Type entityType, out object resultingReader)
{
resultingReader = null;
QueryFilter queryFilter;
string indexName;
// if we failed to compose a query with table's keys and local secondary indexes
if (!translationResult.TryGetQueryFilterForTable(this.TableDefinition, out queryFilter, out indexName))
{
// then trying to find a suitable Global Secondary Index
var matchingIndex = this.TableDefinition
.GlobalSecondaryIndexes.Values
.FirstOrDefault
(
index => translationResult.TryGetQueryFilterForGlobalSeconaryIndex(index, out queryFilter)
);
if (matchingIndex == null)
{
return false;
}
indexName = matchingIndex.IndexName;
}
var queryConfig = new QueryOperationConfig
{
Filter = queryFilter,
CollectResults = false,
ConsistentRead = this._consistentRead,
IndexName = indexName
};
// if a projection is specified - then getting only the required list of fields
if (translationResult.AttributesToGet != null)
{
queryConfig.Select = SelectValues.SpecificAttributes;
queryConfig.AttributesToGet = translationResult.AttributesToGet;
}
var searchResult = this.TableDefinition.Query(queryConfig);
if (string.IsNullOrEmpty(queryConfig.IndexName))
{
this.Log("DynamoDb query: " + translationResult);
}
else
{
this.Log("DynamoDb index query: " + translationResult + ". Index name: " + queryConfig.IndexName);
}
resultingReader = this.CreateReader(searchResult, entityType, translationResult.ProjectionFunc);
return true;
}
