R笔记——基础主要把学习工作中遇到的一些基础知识记下来,方便查看。tryCatch()result <- tryCatch({ }, warning = function(w){ }, error = function(e){ paste0('错误: ', e) #这里的e就是字符串 }, finnally = { } )tryCatch()本身是一个函数,不报错时返回第一个表 ...
public class CountApproxDistinctByKey { public static void main(String[] args) { System.setProperty("hadoop.home.dir", "E:\\hadoop-2.7.1"); SparkConf sparkConf = new SparkConf().setMaster("local").setAppName("Spark_DEMO"); JavaSparkContext sc = new JavaSparkContext(sparkConf); JavaPa...
In the following example, using the APPROX_COUNT_DISTINCT() function with the GROUP BY clause on the customers table. It fetches all names and counts the distinct age values −SELECT NAME, APPROX_COUNT_DISTINCT(AGE) AS Approx_Distinct_AGE FROM customers GROUP BY NAME; ...
The above prototype has a few details that require explaining. First, we've declared this function with the "PtrSafe" attribute as required by 64-bit Excel; if a user is running 32-bit Excel, this attribute should not be included. Second, the prototype includes the full path to the DLL ...