How To Add Header Column To Hive Table Csv

To export a Hive table to a CSV file, it is recommended that you use either a SELECT ON SITE or by passing the output of the select question to a CSV file. In this article, I will learn how to export Hive table to CSV file on HDFS, native list from Hive CLI and Beeline, use HiveQL script and finally export knowledge with column names on header. HiveServer2 and using Beeline tutorial Read: How to add header column to hive csvFirst table, start HiveServer2 and join using beeline as demonstrated below. bin/beeline -u join jdbc:hive2://192.168.1.48:10000 scott tigerChange the handle IP, username and password to match your setup.If you are using an older hive model and want to use Hive CLI, use below choices. $ HIVE_HOME / bin / hive

Create a Table and Load Only a Few Rows

Contents

In an attempt to instantly export the desktop to a CSV file, first create a workbench worker in empty database and shipping table with some knowledge.Follow the steps below to DOWNLOAD knowledge into this workbench.

  • Create an info file (for example, I’m creating a file with comma-separated fields)
  • Add the information file (knowledge.txt) to HDFS. Note that you can also load information from LOCAL without importing it into HDFS.
  • Now use the Hive LOAD command to load the file into the desktop.

DOWNLOAD DATA INPATH ‘/someone/hive/knowledge/knowledge.txt’ INTO TABLE topqa.infooyee; topqa.infooyee The table is filled with knowledge below.hive csv file export table

1. Export from Hive or Beeline Terminal

Hive provides INSERT OVERWRITE DIRECTORY assertion to export Hive table to a file, by default exported knowledge has ^ A (hidden character) as the region separator. In case you want to export the Hive table to a CSV file (with comma delimited fields) use the ROW FORMAT DELETE FUNCTIONS TERMINED BY and specify the area delimiter you need.

1.1 Export Tables to CSV File on HDFS

By default, the INSERT OVERWRITE DIRECTORY command outputs the results of the desired query to the HDFS location. #Exports to HDFS list INSERT OVERWRITE DIRECTORY ‘/person/knowledge/output/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘,’ SELECT * FROM topqa.infooyee; Read more: how to make salted caramel hot chocolate bomb into one export listed on HDFS. Mainly based on your table size, this command can output knowledge into some information. Since our file can be very small, it exports right away as a single file and you should use the HDFS command to check the contents of the exported file. hdfs dfs -cat / person / knowledge / output / export / 000000_0 1, James, 30, M 2, Ann, 40, F 3, Jeff, 41, M 4, Jennifer, 20, FOnce you have the knowledge export to some amount of information, If you want a single file then you might want to concatenate them on the client side as soon as the export is complete. hdfs dfs -cat / person / knowledge / output / export / * | hadoop fs -put – /woman/knowledge/output/export/topqa.information This combines all the information and feeds it back into HDFS at the specified location.

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1.2 Export Tables to CSV File on LOCAL List

Use optional LOCAL option to export knowledge from Hive table to native CSV file. #Exports to LOCAL list INSERT OVERWRITE LOCAL DIRECTORY ‘/tmp/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘,’ SELECT * FROM topqa.infooyee; This exports the results of the selection question in CSV format to export list on /tmp / location. In case your data set is small, you should use the Unix cat command to check the information. cat / tmp / export / 000000_0 1, James, 30, M 2, Ann, 40, F 3, Jeff, 41, M 4, Jennifer, 20, F [email protected]: ~ / hive $ When you have a large workbench this will output the information into a number of halves, You can mix them right into a single file using the Unix cat command as proven under. cat / tmp / export / *> topqa.informationPlease note: Since Hive uses MapReduce or Tez behind the scenes to run queries, they usually generate some half of the information when you already have a big knowledge base, exporting the information along with the column names on the header is not the way good for every half output. information associated with a title document. In case if you want to export with headers for any purpose, I have some examples right below to export with column names.

2. Export Hive Desk to CSV using Beeline

In this regard, I will clarify exporting a Hive table to CSV using the beeline CLI right away.

2.1 Export using Beeline to HDFS Listing

To replace connection with Hive / Beeline CLI and operating instructions may not be an option for some use cases. In addition, you will be able to export instantly using the Hive/Beeline command. #Exports to HDFS location bin / beeline -u jdbc: hive2://192.168.1.148: 10000 -n scott -p tiger -e “INSERT OVERWRITE DIRECTORY ‘/user/data/output/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘ , ‘SELECT * FROM topqa.infooyee’

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2.2 Export using Beeline to LOCAL list

Read more: how to start leaf blower Use optional LOCAL clause to export CSV file from Hive table to native list. #Exports to LOCAL list bin / beeline -u jdbc: hive2://192.168.1.148: 10000 -n scott -p tiger -e “INSERT OVERWRITE LOCAL DIRECTORY ‘/tmp/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘,’ SELECT * FROM topqa.infooyee”

2.3 Export Hive Desk to CSV file with Header

By default, Beeline terminal outputs information to a table format, by changing the format to CSV2, Hive beeline returns the terminals in CSV format. By passing this output right into a CSV file, we get a CSV file with headers. See this in motion. #This outputs with the region name on header bin / beeline -u jdbc: hive2:// localhost: 10000 -n scott -p tiger -outputformat = csv2 -e “SELECT * FROM topqa.infooyee”> topqa.information This renders the results of the select query in CSV format into the file topqa.information on the current original list. In case your data set is small, you should use the Unix cat command to check the information. cat topqa.information topqa.information, worker.identify, worker.age, worker.uality 1, James, 30, M 2, Ann, 40, F 3, Jeff, 41, M 4, Jennifer, 20, F [email protected]: ~ / hive $

3. Export Hive Desk to CSV using Hive CLI Command

If you are using an older model of Hive, below are completely different examples to export the workbench right into a CSV file. This example exports to an HDFS list. #Exports to HDFS list bin / hive -e “INSERT OVERWRITE DIRECTORY ‘/user/data/output/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘,’ SELECT * FROM topqa.infooyee” This version exports to LOCAL list. #Exports to LOCAL list bin / hive -e “INSERT OVERWRITE LOCAL DIRECTORY ‘/tmp/export’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘, ‘ SELECT * FROM topqa.infooyee” Another instance of exporting to the LOCAL list. right here we use sed command to switch tabs with comma delimited. # Output LOCAL list bin / hive -e “SELECT * FROM topqa.infooyee” | sed ‘s /[t]/, /g ‘>topqa.informationYou can also specify the property that sets topqa.information=true earlier than SELECT to output a CSV file with region/column names on the header. #This output with region name on header bin / hive -e ‘set topqa.infoer = true; SELECT * FROM topqa.infooyee ‘| sed ‘s /[t]/, /g ‘> topqa.information In case your Hive model is useful, you can do that too. This is an obvious method and doesn’t have to use sed to switch tabs or specific characters with commas. # Output LOCAL list using CSV2 choice bin / hive -outputformat = csv2 -e ‘SELECT * FROM topqa.infooyee’> topqa.information

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Inference

In this article you learned how to export the table and the results of the question to a CSV file on an HDFS location and the LOCAL location is also recognized as an export using hive, beeline and from the respective terminals of them. Have fun learning!! Read more: how to make a necklace for wine glasses

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