CODEWITHSUNDEEP
linuxbashshellfor-loop
WhimsicalWhale
WhimsicalWhale

Reputation: 135

Nested for loop for months within a year

I'm currently writing a shell scrip that will query some hive tables for record counts per month for a list of tables and then extract the total count values as a .txt file. I currently have code that will query all the tables on a yearly basis, but how can I best have it looping on a monthly per year basis as well?

For example, right now my script will loop through each year I pass (year=2001, 2002,2003,...) and query my tables and extract the files. I would like to have it loop per month for each year so that there would ideally be 12 files per year and continue looping for whatever years I assign.

Example pseudocode below for what I currently have:

#!/usr/bin/sh    
years=2001,2002,2003,2004

for year in $(echo ${years} | sed "s/,/ /g")
do 
    select_sql="INSERT OVERWRITE LOCAL DIRECTORY <path> ROW FORMAT DELIMITED FIELDS TERMINATED BY '~' select * from tbl where year(date)=$year"
    beeline -u "<jdbc connection>" --hiveconf -e "$select_sql"

done

Upvotes: 0

Views: 870

Answers (2)

Feng
Feng

Reputation: 4038

This question has a bash tag, but the interpreter is /usr/bin/sh.

Anyway, let's use bash.

#!/bin/bash

for clause in "year(date)="{2001,2002,2003,2004}" and month(data)='"{Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec}"'"
do
    select_sql="INSERT OVERWRITE LOCAL DIRECTORY <path> ROW FORMAT DELIMITED FIELDS TERMINATED BY '~' select * from tbl where $clause"
    echo "$select_sql"
    #beeline -u "<jdbc connection>" --hiveconf -e "$select_sql"
done

Upvotes: 1

sal
sal

Reputation: 3593

A nested loop and an array in this case could be something like:

years=2001,2002,2003,2004
months=(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec)

for year in $(echo ${years} | sed "s/,/ /g")
do
    for month in "${months[@]}"
    do
        # do the query and file saving here
        echo "$year $month"
    done
done

Upvotes: 0

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