Example: create new database from existing database and extract all tables from old DB to new DB

SYNTAX:

if [ $# -eq 1 ]

then

echo "valid database"

db_name=$1

else

echo "please enter database"

fi

hive -e "use $olddb;show tables;">Old_db_tables.txt

files="$(<Old_db_tables.txt)"

hive -e "create database $newdb;use $newdb; "

for file1 in $files;

do

type=`eval "hive -e 'create table $newdb.$file1 as select * from $olddb.$file1;"

done

if grep -ie "failed"

then

awk {"print $1"}>error.txt

fi

done

hive -e "use $newdb;show tables;">hive_tables.txt;

EXAMPLE:

[adimulamvenkat19851609@cxln4 ~]$ cat db_create.sh

 #Script for create new database from existing database and extract all tables from old DB to new DB

hive -e "use mhtprabhu;show tables;">Old_db_tables.txt

files="$(<Old_db_tables.txt)"

hive -e "create database mhtprabhu_new;use mhtprabhu_new; "

for file1 in $files;

do

hive -e "create table mhtprabhu_new.$file1 as select * from mhtprabhu.$file1;"

done

hive -e "use mhtprabhu_new;show tables; ">New_db_tables.txt

Verify :

hive> show databases like 'mht*';
mhtprabhu
mhtprabhu_new


[adimulamvenkat19851609@cxln4 ~]$ cat Old_db_tables.txt
emp_sample
employee_data
hari_tab
prabhu_tab
student
student4
student5
student_part


[adimulamvenkat19851609@cxln4 ~]$ cat New_db_tables.txt
emp_sample
employee_data
hari_tab
prabhu_tab
student
student4
student_p
student5art