CODEWITHSUNDEEP
hadoophivebigdata
user4881368
user4881368

Reputation:

Selecting Data from mulitple tables in Hive

I have multiple tables in Hive with different schemas.

I want to select top 20 rows from each table and dump into csv file.

Is there any way to do it. As all I have found is to dump data from a single table to csv.

Any help would be appreciated!!

Upvotes: 0

Views: 122

Answers (1)

Manish Saraf Bhardwaj
Manish Saraf Bhardwaj

Reputation: 1058

If you have different schema.

1.Below sample code will produce multiple csv files.

#!/bin/bash

  tbs=$(hive -S -e "show tables")
  for tb in $tbs
  do
    hive -e "set hive.cli.print.header=true; SELECT * FROM $tb LIMIT 20;" | sed 's/[\t]/,/g' > $tb.csv
  done

2.Below sample code will produce single csv file.

#!/bin/bash

  tbs=$(hive -S -e "show tables")
  for tb in $tbs
  do
    echo "Table Name : "$tb >> sampleData.csv
    hive -e "set hive.cli.print.header=true; SELECT * FROM $tb LIMIT 20;" | sed 's/[\t]/,/g' >> sampleData.csv
  done

Upvotes: 1

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