如何将变量作为SQL Server 2016 R服务的输出返回？

Question

我有以下代码

EXECUTE sp_execute_external_script
    @language = N'R',
    @script = N'

        table1 <- unserialize(Table1_Data)
        table2 <- unserialize(Table2_Data)
        df_1 <-merge(x=table1,y=table2,
              by=c("batchId","BatchTaskID"),all=TRUE)
        df_2 <- df_1 %>% filter(batchId == 5 & BatchTaskStatus == 'N') %>%
             arrange(desc(BatchTaskRunID))
        if(nrow(df_2) > 1){ 
        result = TRUE
        return(result)
            }
        else {
            result = FALSE
            return(result)
            }

        OutputDataSet <- result
    ',
    @params = N'@Table1_Data VARBINARY(MAX), @Table2_Data VARBINARY(MAX)',
    @Table1_Data = @Table1_Data,
    @Table2_Data = @Table2_Data
    WITH RESULT SETS (( INT ));

如何仅从输出数据集返回标志值而不是整个数据帧？