Question

下面是代码块并收到错误

> creating a temporary views 
sqlcontext.sql("""CREATE TEMPORARY VIEW temp_pay_txn_stage
     USING org.apache.spark.sql.cassandra
     OPTIONS (
       table "t_pay_txn_stage",
       keyspace "ks_pay",
       cluster "Test Cluster",
       pushdown "true"
     )""".stripMargin)

sqlcontext.sql("""CREATE TEMPORARY VIEW temp_pay_txn_source
     USING org.apache.spark.sql.cassandra
     OPTIONS (
       table "t_pay_txn_source",
       keyspace "ks_pay",
       cluster "Test Cluster",
       pushdown "true"
     )""".stripMargin)

查询以下视图，以便能够从源中不存在的阶段获取新记录。

Scala> val df_newrecords = sqlcontext.sql("""Select UUID(),
 | |stage.order_id,
 | |stage.order_description,
 | |stage.transaction_id,
 | |stage.pre_transaction_freeze_balance,
 | |stage.post_transaction_freeze_balance,
 | |toTimestamp(now()),
 | |NULL,
 | |1 from temp_pay_txn_stage  stage left join temp_pay_txn_source source on stage.order_id=source.order_id and stage.transaction_id=source.transaction_id where
 | |source.order_id is null and source.transaction_id is null""")`



org.apache.spark.sql.AnalysisException: Undefined function: 'uuid()'. This function is neither a registered temporary function nor a permanent function registered in the database 'default'.; line 1 pos 7

我正在尝试生成UUID，但是收到此错误。

Answer 1

这是一个简单示例如何生成timeuuid：

import org.apache.spark.sql.SQLContext    
val sqlcontext = new SQLContext(sc)

import sqlcontext.implicits._

//Import UUIDs that contains the method timeBased()
import com.datastax.driver.core.utils.UUIDs

//user define function timeUUID  which will retrun time based uuid      
val timeUUID = udf(() => UUIDs.timeBased().toString)

//sample query to test, you can change it to yours
val df_newrecords = sqlcontext.sql("SELECT 1 as data UNION SELECT 2 as data").withColumn("time_uuid", timeUUID())

//print all the rows
df_newrecords.collect().foreach(println)

输出：

[1,9a81b3c0-170b-11e7-98bf-9bb55f3128dd]
[2,9a831350-170b-11e7-98bf-9bb55f3128dd]

来源：https://stackoverflow.com/a/37232099/2320144 https://docs.datastax.com/en/drivers/java/2.0/com/datastax/driver/core/utils/UUIDs.html#timeBased--

无法在Spark SQL中生成UUID

1 个答案: