How can I insert the content of the variable into single quotes inside the INSERT INTO command? - sql

Question

I created a text file. The name of this is "test.txt" and the content is first part below. I also created script with the name insert.sh.
I run the command with ./insert.sh test.txt.
If the words / strings are in single quotes, it will insert the words into the columns. Also it will insert numbers without single quotes. The csv that I will eventually use won't have single quotes and I don't want to change the data.
How can I insert the content of the variable into single quotes inside the INSERT INTO command?
I am using psql.
Text file, test.txt
'one','ten','hundred'
'two','twenty','twohundred'
Script, insert.sh:
#!/bin/bash
while read cell
do
name=$cell
echo "$cell"
####Insert from txt into table####
sudo -u username -H -- psql -d insert_test -c "
INSERT INTO first (ten, hundred, thousend) VALUES ($cell);
"
done < $1
something like this:
INSERT INTO first (ten, hundred, thousend) VALUES (INSERT" $cell "QUOTES);
UPDATE:
I changed the code. I added the single quotes around $cell as you suggested.
#!/bin/bash
while read cell
do
name=$cell
echo "$cell"
####Insert from txt into table####
sudo -u username -H -- psql -d insert_test -c "
INSERT INTO first (ten, hundred, thousend) VALUES ('$cell');
"
done < $1
and I removed the quotes out of the text file since the csv file that I want to use later wont have any single quotes.
new text file.
one,ten,hundred
two,twenty,twohundred
and im getting the error:
one,two,three
ERROR: INSERT has more target columns than expressions
LINE 2: INSERT INTO first (ten, hundred, thousend) VALUES ('one,two,...

Answer 1

You need to modify the $IFS (Internal Field Separator) variable to determine the line separator used by Bash. Since you used a CSV like file, you IFS come to , character, thus this is the result $IFS=,. Note that if you need to do others stuff in you script, you need to redefine the $IFS var to the original state, so you need to store it in an temportal variable before you change it, something like $OLDIFS=$IFS.
readline read the entire line and separate the values depending on $IFS var, thus you need to write the adecauted quantity of var where readline will store the words, i.e., if you line have 3 words, you need to give 3 vars to readline, e.g.: file: foo,baz,bar, readline -r word1 word2 word3. If you don't give the correct amount of vars, readline will store the rest of word in a single var, that is your problem.
So, a solution to your problem would be:
#!/bin/bash
$OLDIFS=$IFS # If you need to do more stuff.
while IFS=, read -r word1 word2 word3
do
sudo -u username -H -- psql -d insert_test -c
"INSERT INTO first (ten, hundred, thousend) VALUES (${word1}, ${word2}, ${word3});"
done < $1
$IFS=$OLDIFS # Same of line 2.
# ...
NOTE: This is insecure because lead with easily to a SQL injection. If you use this, only use in a local database that don't have any sensetive data.