在Spark SQL中,可以使用cast函数来实现Long类型到String类型的转换。cast函数用于强制类型转换,可以将Long类型的数据转换为String类型。下面是一个示例代码: ```sql SELECT cast(12345 AS STRING) AS converted_string 1. 2. 上面的代码中,我们将Long类型的数据`12345`通过`cast`
-- 创建示例表CREATETABLEsales_data(idINT,revenueDECIMAL(10,2));-- 插入示例数据INSERTINTOsales_dataVALUES(1,123.45);INSERTINTOsales_dataVALUES(2,67.89);INSERTINTOsales_dataVALUES(3,100.00);-- 执行数值转字符查询SELECTid,CAST(revenueASSTRING)ASrevenue_strFROMsales_data; 1. 2. 3. 4. 5. 6. 7...
case length(cast( month(current_date) as string) ) when 1 then concat( '0' , cast( month(current_date) as string) ) else month(current_date) end ) as month, day(current_date) as day, ( case length(hour(current_timestamp)) when 1 then concat( '0' , cast ( hour(current_times...
read.json("/opt/module/spark-local/people.json") df: org.apache.spark.sql.DataFrame = [age: bigint, name: string] 2)创建一个样例类 scala> case class Person(name: String,age: Long) defined class Person 3)将DataFrame转化为DataSet scala> df.as[Person] res5: org.apache.spark.sql.Da...
select t1.id, t1.id_rand, t2.name from ( select id , case when id = null then concat(‘SkewData_’, cast(rand() as string)) else id end as id_rand from test1 where statis_date =‘20221130’) t1 left join test2 t2 on t1.id_rand = t2.id 针对Spark3,可以在EMR控制台Spark3服...
功能描述:用sql创建一个数组(原来生成一个数组这么简单,我之前经常用split('1,2,3',',')这种形式来生成数组,现在看来用array函数最方便快捷) 版本:1.1.0 是否支持全代码生成:支持 用法: --生成一维数组 select array(1, 3, 5) as arr; +---+ |arr | +---+ |[1, 3, 5]| +---+ ...
1.sparksql-shell交互式查询 就是利用Spark提供的shell命令行执行SQL 2.编程 首先要获取Spark SQL编程"入口":SparkSession(当然在早期版本中大家可能更熟悉的是SQLContext,如果是操作hive则为HiveContext)。这里以读取parquet为例: 代码语言:javascript 代码运行次数:0 ...
- cast('12.5' as decimal) 结果是:12 精度和小数位数默认值分别是18与0。如果在decimal类型中不提供这两个值,将截断小数部分,并不会像第二个例子一样报错。 三、数学运算 round 四舍五入 floor 取左值 ceil 取右值 例子: select round(1.2356); +---+ |round(1.2356, 0)| +---+ | 1| +---+...
转化为Dataframe我们可以很方便地使用Spark SQL查询一些复杂的结构 代码语言:txt AI代码解释 val cloudtrailEvents = rawRecords .select(explode($"records") as 'record) .select( unix_timestamp( $"record.eventTime", "yyyy-MM-dd'T'hh:mm:ss").cast("timestamp") as 'timestamp, $"record.*") ...
spark.sql.function.concatBinaryAsString FALSE When this option is set to false and all inputs are binary,functions.concat returns an output as binary. Otherwise, it returns as a string. spark.sql.function.eltOutputAsString FALSE When this option is set to false and all inputs are binary, ...