In the previous post, I shared shell script like store psql result into record array.
In this post, I am sharing one more shell script to store the result of psql SELECT query into a Variable of Bash Shell Script.

This handy script is useful for a beginner who just started to write a PostgreSQL DBA Bash Shell Script. You need this kind of demonstration to store the result of psql query into variable mostly like count of records.

The value of this variable we can use for further validation something like data exists or not in the Table.

In the below script, I used two variables to store the count of a table, but do not forget to notice option ‘-t’ in the second query which returns only tuple value and without option ‘-t’ it returns all formatted text as well like column name, returned a row count.

We need only tuple value so we must use ‘-t’ option. Please check the below demonstration.

#!/bin/bash

DB_NAME=$1
RecordCount1=$( psql -d ${DB_NAME} -c "select count(1) from tbl_students" )
RecordCount2=$( psql -d ${DB_NAME} -t -c "select count(1) from tbl_students" )

echo "RecordCount1:"$RecordCount1
echo "RecordCount2:"$RecordCount2

The result:

RecordCount1: count ------- 9 (1 row)
RecordCount2: 9