How to insert string start with `'` to postgresql when `psql` in bash？ - postgresql

Question

#!/bin/bash
set -e
res_dir='/home/me'
db_port='5432'
db_name='test'
db_user='postgres'
db_password='passwoed'
table_name='record'
#input something start with \ will get error
read -p 'input site: ' site_input
res="'string";
psql postgresql://"$db_user":"$db_password"#localhost:"$db_port"/"$db_name" << EOF
INSERT INTO "$table_name" (site,res) VALUES ($site_input,$res);
EOF
Above script will get error when your input string start with '.
input site: 'jh
ERROR: syntax error at or near "string"
LINE 1: INSERT INTO "record" (site,res) VALUES ('jh,'string);
^
I also tried other methods as below,but none workable.
psql postgresql://"$db_user":"$db_password"#localhost:"$db_port"/"$db_name" << EOF
INSERT INTO "$table_name" (site,res) VALUES ('|| $site_input || ','|| $res || ');
EOF
psql postgresql://"$db_user":"$db_password"#localhost:"$db_port"/"$db_name" << EOF
INSERT INTO "$table_name" (site,res) VALUES (quote_literal($site_input),quote_literal($res));
EOF
How to insert string start with ' to postgresql when psql in bash？

Answer 1

You can escape single quotes by doubling them :
#!/bin/bash
set -e
res_dir='/home/me'
db_port='5432'
db_name='test'
db_user='postgres'
db_password='passwoed'
table_name='record'
#input something start with \ will get error
read -p 'input site: ' site_input
res="'string";
######## Doubling single quotes
site_input="${site_input//\'/\'\'}"
res="${res//\'/\'\'}"
######## Updated with '$site_input','$res'
psql postgresql://"$db_user":"$db_password"#localhost:"$db_port"/"$db_name" << EOF
INSERT INTO "$table_name" (site,res) VALUES ('$site_input','$res');
EOF
//\'/\'\' replaces all single quote ' by ''
For more information, see Parameter expansion