public async Task <bool> ExecuteAsync(CancellationToken cancellationToken)
{
_request.ConditionExpression = _converter.ConvertConditions(_table.Options);
try {
await _table.DynamoClient.DeleteItemAsync(_request);
return(true);
} catch (ConditionalCheckFailedException) {
return(false);
}
}
public IDynamoTableTransactWriteItems End()
{
// combine update actions
var result = new List <string>();
var modifiedAttributeName = _converter.GetAttributeName("_m");
var modifiedAttributeValue = _converter.GetExpressionValueName(DateTimeOffset.UtcNow.ToUnixTimeMilliseconds());
result.Add($"SET {string.Join(", ", _setOperations.Append($"{modifiedAttributeName} = {modifiedAttributeValue}"))}");
if (_removeOperations.Any())
{
result.Add($"REMOVE {string.Join(", ", _removeOperations)}");
}
if (_addOperations.Any())
{
result.Add($"ADD {string.Join(", ", _addOperations)}");
}
if (_deleteOperations.Any())
{
result.Add($"DELETE {string.Join(", ", _deleteOperations)}");
}
// update request
_update.ConditionExpression = _converter.ConvertConditions(_parent.Table.Options);
_update.UpdateExpression = string.Join(" ", result);
return(_parent);
}
//--- Methods ---
private void PrepareRequest(bool fetchAllAttributes)
{
// inherit the expected types from the query select construct
foreach (var expectedType in _queryClause.TypeFilters)
{
_converter.AddExpectedType(expectedType);
}
// initialize request
_request.IndexName = _queryClause.IndexName;
_request.KeyConditionExpression = _queryClause.GetKeyConditionExpression(_converter);
_request.FilterExpression = _converter.ConvertConditions(_table.Options);
_request.ProjectionExpression = _converter.ConvertProjections();
// NOTE (2021-06-23, bjorg): the following logic matches the default behavior, but makes it explicit
// if `ProjectionExpression` is set, only return specified attributes; otherwise, for an index, return projected attributes only; for tables, return all attributes from each row
if (_request.ProjectionExpression is null)
{
if ((_request.IndexName is null) || fetchAllAttributes)
{
_request.Select = Select.ALL_ATTRIBUTES;
}
else
{
_request.Select = Select.ALL_PROJECTED_ATTRIBUTES;
}
}
public IDynamoTableTransactWriteItems End()
{
_put.ConditionExpression = _converter.ConvertConditions(_parent.Table.Options);
return(_parent);
}
