Well my version of Spark is 1.5.2
On 21/02/2016 23:54, Jacky Wang wrote:
> df.write.saveAsTable("db_name.tbl_name") // works, spark-shell, latest spark
> version 1.6.0
> df.write.saveAsTable("db_name.tbl_name") // NOT work, spark-shell, old spark
> version 1.4
>
> --
>
> Jacky Wang
>
> At 2016-02-21 17:35:53, "Mich Talebzadeh" <m...@peridale.co.uk> wrote:
>
> I looked at doc on this. It is not clear what goes behind the scene. Very
> little documentation on it
>
> First in Hive a database has to exist before it can be used so sql("use
> mytable") will not create a database for you.
>
> Also you cannot call your table mytable in database mytable!
>
> Remember in Hive the hierarchy is the database followed by tables.
>
> If you want to create a Hive database (I would not for every table) for this
> purpose you can do
>
> scala> sql("create database if not exists mytable_db")
>
> res10: org.apache.spark.sql.DataFrame = [result: string]
>
> scala> sql("use mytable_db")
>
> res12: org.apache.spark.sql.DataFrame = [result: string]
>
> This puts you in the context of mytable_db database
>
> If you do
>
> hdfs dfs -ls /user/hive/warehouse
>
> You will see a directory called mytable_db.db is created
>
> /user/hive/warehouse/mytable.db
>
> Then you can create a table in Hive in mytable_db if you wish. The way I do
> it personally is to register your DF as a temporary table and do
> insert/select into Hive table
>
> scala> sql("use mytable_db")
>
> res21: org.apache.spark.sql.DataFrame = [result: string]
>
> scala> """
>
> | CREATE TABLE mytable (
>
> | INVOICENUMBER INT
>
> | ,PAYMENTDATE timestamp
>
> | ,NET DECIMAL(20,2)
>
> | ,VAT DECIMAL(20,2)
>
> | ,TOTAL DECIMAL(20,2)
>
> | )
>
> | COMMENT 'a test table'
>
> | STORED AS ORC
>
> | TBLPROPERTIES ( "orc.compress"="ZLIB" )
>
> | """
>
> res22: String =
>
> "
>
> CREATE TABLE mytable (
>
> INVOICENUMBER INT
>
> ,PAYMENTDATE timestamp
>
> ,NET DECIMAL(20,2)
>
> ,VAT DECIMAL(20,2)
>
> ,TOTAL DECIMAL(20,2)
>
> )
>
> COMMENT 'a test table'
>
> STORED AS ORC
>
> TBLPROPERTIES ( "orc.compress"="ZLIB" )
>
> "
>
> scala> sql(sqltext)
>
> res6: org.apache.spark.sql.DataFrame = [result: string]
>
> My DF is called "a" below so I register it as a temp table called tmp
>
> a.toDF.registerTempTable("tmp")
>
> Then just insert/select into Hicve table mytable from tmp
>
> scala> sqltext = "INSERT INTO mytable SELECT * FROM tmp"
>
> sqltext: String = INSERT INTO mytable SELECT * FROM tmp
>
> scala> sql(sqltext)
>
> res10: org.apache.spark.sql.DataFrame = []
>
> scala> sql("select count(1) from mytable").show
>
> +---+
>
> |_c0|
>
> +---+
>
> | 65|
>
> HTH
>
> Dr Mich Talebzadeh
>
> LinkedIn _
> https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw
> [1]_
>
> http://talebzadehmich.wordpress.com [2]
>
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> FROM: Glen [mailto:cng...@gmail.com]
> SENT: 21 February 2016 03:26
> TO: gen tang <gen.tan...@gmail.com>
> CC: user@spark.apache.org
> SUBJECT: Re: how to set database in DataFrame.saveAsTable?
>
> Any example code?
>
> In pyspark:
>
> sqlContex.sql("use mytable")
>
> my_df.saveAsTable("tmp_spark_debug", mode="overwrite")
>
> 1. The code above seems not register the table in hive. I have to create
> table from hdfs in hive, it reports some format error: rcformat and parquet.
>
> 2. Rerun the saveAsTable using mode="overwrite" in saveAsTable, it reports
> the table already exists.
>
> 3. Sometimes it creates a directory in hive/warehouse/tmp_spark_debug, not in
> hive/warehouse/mytable/tmp_spark_debug.
>
> My goal is simple:
>
> df.saveAsTable('blablabla') // create a hive table in some database, then it
> can be visited by hive.
>
> I tried lots of time, it seems there are lots of bug in pyspark. Or my mehtod
> is wrong?
>
> 2016-02-21 10:04 GMT+08:00 gen tang <gen.tan...@gmail.com>:
>
> Hi,
>
> You can use
>
> sqlContext.sql("use <your database>")
>
> before use dataframe.saveAsTable
>
> Hope it could be helpful
>
> Cheers
>
> Gen
>
> On Sun, Feb 21, 2016 at 9:55 AM, Glen <cng...@gmail.com> wrote:
>
> For dataframe in spark, so the table can be visited by hive.
>
> --
>
> Jacky Wang
--
Jacky Wang
--
Dr Mich Talebzadeh
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