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我想將Spark數據集寫入現有的postgresql表（不能更改表格元數據，如列類型）。這張表的其中一列是HStore，它造成了麻煩。如何使用Spark數據集寫入PostgreSQL hstore
我看到下面的異常，當我啓動寫（這裏的原始地圖爲空時逃走了給出了一個空字符串）：
Caused by: java.sql.BatchUpdateException: Batch entry 0 INSERT INTO part_d3da09549b713bbdcd95eb6095f929c8 (.., "my_hstore_column", ..) VALUES (..,'',..) was aborted. Call getNextException to see the cause.
at org.postgresql.jdbc.BatchResultHandler.handleError(BatchResultHandler.java:136)
at org.postgresql.core.v3.QueryExecutorImpl$1.handleError(QueryExecutorImpl.java:419)
at org.postgresql.core.v3.QueryExecutorImpl$ErrorTrackingResultHandler.handleError(QueryExecutorImpl.java:308)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2004)
at org.postgresql.core.v3.QueryExecutorImpl.flushIfDeadlockRisk(QueryExecutorImpl.java:1187)
at org.postgresql.core.v3.QueryExecutorImpl.sendQuery(QueryExecutorImpl.java:1212)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:351)
at org.postgresql.jdbc.PgStatement.executeBatch(PgStatement.java:1019)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$.savePartition(JdbcUtils.scala:222)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$saveTable$1.apply(JdbcUtils.scala:300)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$saveTable$1.apply(JdbcUtils.scala:299)
at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$28.apply(RDD.scala:902)
at org.apache.spark.rdd.RDD$$anonfun$foreachPartition$1$$anonfun$apply$28.apply(RDD.scala:902)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1899)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1899)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:70)
at org.apache.spark.scheduler.Task.run(Task.scala:86)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.postgresql.util.PSQLException: ERROR: column "my_hstore_column" is of type hstore but expression is of type character varying
這是怎麼了，我這樣做：
def escapePgHstore[A, B](hmap: Map[A, B]) = {
hmap.map{case(key, value) => s""" "${key}"=>${value} """}.mkString(",")
}
...
val props = new Properties()
props.put("user", "xxxxxxx")
props.put("password", "xxxxxxx")
ds.withColumn("my_hstore_column", escape_pg_hstore_udf($"original_column"))
.drop("original_column")
.coalesce(1).write
.mode(org.apache.spark.sql.SaveMode.Append)
.option("driver", "org.postgresql.Driver")
.jdbc(jdbcUrl, hashedTablePartName, props)
如果我不使用escapePgHstore我看到下面的錯誤逃避地圖[字符串，龍]爲String的original_column：
java.lang.IllegalArgumentException: Can't get JDBC type for map<string,bigint>
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$org$apache$spark$sql$execution$datasources$jdbc$JdbcUtils$$getJdbcType$2.apply(JdbcUtils.scala:137)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$org$apache$spark$sql$execution$datasources$jdbc$JdbcUtils$$getJdbcType$2.apply(JdbcUtils.scala:137)
at scala.Option.getOrElse(Option.scala:121)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$.org$apache$spark$sql$execution$datasources$jdbc$JdbcUtils$$getJdbcType(JdbcUtils.scala:136)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$7.apply(JdbcUtils.scala:293)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$$anonfun$7.apply(JdbcUtils.scala:292)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.mutable.ArrayOps$ofRef.map(ArrayOps.scala:186)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$.saveTable(JdbcUtils.scala:292)
at org.apache.spark.sql.DataFrameWriter.jdbc(DataFrameWriter.scala:441)
at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.collection.immutable.List.foreach(List.scala:381)
at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)
at scala.App$class.main(App.scala:76)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:736)
at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:185)
at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:210)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:124)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
什麼是正確的方式讓火花寫入有效的hstore數據類型？
這個工作對我來說太棒了！你爲我節省了****時間，這是我能找到的唯一信息。也就是說，我確實發現了一個關鍵部分：您寫入的'hstore'列必須已經存在。如果Spark正在使用的'SaveMode'設置爲「覆蓋」，Postgres將永遠沒有機會嘗試將文本解析到'hstore'列中; Spark只是告訴Postgres它是一個「文本」列。 – mtrewartha