In PostgreSQL, we can use the quote_ident() function to quote identifiers in a SQL statement string.

Quotes are only added if necessary. Any embedded quotes are doubled.

Examples

Here’s an example to demonstrate:

SELECT quote_ident('User Logins');

Result:

"User Logins"

Here are more examples:

\x
SELECT 
    quote_ident('user') AS "user",
    quote_ident('users') AS "users",
    quote_ident('user_logins') AS "user_logins",
    quote_ident('users_logins') AS "users_logins",
    quote_ident('users'' logins') AS "users'' logins",
    quote_ident(E'users\' logins') AS "users\' logins",
    quote_ident('users "logins"') AS "users ""logins""",
    quote_ident(' ') AS " ",
    quote_ident('100') AS "100";

Result:

user           | "user"
users          | users
user_logins    | user_logins
users_logins   | users_logins
users'' logins | "users' logins"
users\' logins | "users' logins"
users "logins" | "users ""logins"""
               | " "
100            | "100"

Passing a Null Value

Passing a null value results in null being returned:

SELECT quote_ident(null);

Result:

null