Обсуждение: Space Stalker in SQL Output
Why would a psql statement insert a leading space into the output, which is a single integer value? The leading space caused my job call to fail elsewhere in the same shell script as the psql call. Here is the anonymized version of the psql call to assign a value to a shell script variable: IDz=`psql -d proddb -U produser -h 10.9.999.99 -p 99900 -t < last_id.sql` The output is simply a max(id) value, which is defined as an integer data type in the source table column. The output looked like this (notice the leading space before the integer value): echo “IDz =${IDz} IDz =’ 100’ The last_id.sql itself is simply: select max(id) from prodtable; I'm using: PostgreSQL 9.5.0 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16), 64-bit I fixed the output in the shell script with a tr command but why should that be necessary? What is causing the space to be prepended to integer value? ID=`echo ${IDz} | tr -d ''` IDz =’100’ Knowing the root cause of the space stalker would be most helpful. Thanks for your help! Sue -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Susan E Hurst Principal Consultant Brookhurst Data LLC Email: susan.hurst@brookhurstdata.com Mobile: 314-486-3261
Susan Hurst <susan.hurst@brookhurstdata.com> writes: > Why would a psql statement insert a leading space into the output, > which is a single integer value? > > The leading space caused my job call to fail elsewhere in the same > shell script as the psql call. Here is the anonymized version of the > psql call to assign a value to a shell script variable: > > IDz=`psql -d proddb -U produser -h 10.9.999.99 -p 99900 -t < > last_id.sql` Get in the habit of including -A which gets rid of alignment padding in psql output. As in... shellvar=`psql -Atqc 'select froboz;'` $db HTH -- Jerry Sievers Postgres DBA/Development Consulting e: postgres.consulting@comcast.net p: 312.241.7800
Wow! The -A option worked perfectly! Thanks for the syntax lesson Steve and Jerry! Sue --- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Susan E Hurst Principal Consultant Brookhurst Data LLC Email: susan.hurst@brookhurstdata.com Mobile: 314-486-3261 On 2018-06-27 14:38, Jerry Sievers wrote: > Susan Hurst <susan.hurst@brookhurstdata.com> writes: > >> Why would a psql statement insert a leading space into the output, >> which is a single integer value? >> >> The leading space caused my job call to fail elsewhere in the same >> shell script as the psql call. Here is the anonymized version of the >> psql call to assign a value to a shell script variable: >> >> IDz=`psql -d proddb -U produser -h 10.9.999.99 -p 99900 -t < >> last_id.sql` > > Get in the habit of including -A which gets rid of alignment padding in > psql output. > > As in... > > shellvar=`psql -Atqc 'select froboz;'` $db > > HTH
On 06/27/2018 12:45 PM, Susan Hurst wrote: > Wow! The -A option worked perfectly! > > Thanks for the syntax lesson Steve and Jerry! If you are going to be doing lots of scripting with Postgres, you might want to take a look here: https://github.com/jconway/shebang HTH, Joe -- Crunchy Data - http://crunchydata.com PostgreSQL Support for Secure Enterprises Consulting, Training, & Open Source Development