I am trying to query a kubernetes Postgres pod using a bash script where i want to allow user to enter a variable and then use that variable to query. My bash script is as follows:
#!/bin/bash
echo "give a last name"
read t
kubectl exec -it postgres-pod -- bash -c "psql -U postgres -c 'Select * from users WHERE last_name=\"$t\"'"
I have tried all combinations of single and double quotes but i am unable to pass a string type username. Any suggestions would be appreciated
The simple, but bad, solution is
bash -c "psql -U postgres -c \"Select * from users WHERE last_name='$t'\""
This gets the quoting right, but is vulnerable to SQL injection. What if the variable t contains a value with a single quote?
Dealing with that is not so simple; the only way I could think of is using psql variables like this:
echo "Select * from users WHERE last_name = :'var'" | bash -c "psql -U postgres -v var=\"$t\""
Not sure why you need bash, should this work ?
kubectl exec -it postgres-pod -- psql -U postgres -c "SELECT * FROM users WHERE last_name='$t';"
i solved it using @James Brown's answer above:
bash -c "psql -U postgres -c \"Select * from users WHERE last_name='$t';\""
bash -c "psql -U postgres -c \"Select * from users WHERE last_name='$t';\""