Column Does Not Exist Quoted Identifier Case

PostgreSQL follows the SQL standard for identifiers: an unquoted identifier is folded to lowercase before lookup, while a double-quoted identifier is taken verbatim, preserving case. The columns here were created as "userId" and "createdAt" (quoted), so their real names contain uppercase letters. Writing userId without quotes asks PostgreSQL to find userid, which does not exist, so it raises 42703.

The HINT's fuzzy match surfaces the close camelCase name. This is purely a naming-resolution issue -- the rows, types, and indexes are all intact. There are two correct responses: quote the identifier everywhere it is used (immediate, but fragile because every reference must remember the quotes), or rename the columns to lower_snake_case so that an unquoted reference resolves naturally and quoting is never needed again. There are two correct responses: quote the identifier everywhere it is used (immediate, but fragile because every reference must remember the quotes), or rename the columns to lower_snake_case so that an unquoted reference resolves naturally and quoting is never needed again.

Free Tier -- Basic Approach

First, see the columns as they are actually stored and count the ones that are not all-lowercase. Those are precisely the names that must be quoted to be referenced -- the source of the error.

SELECT column_name FROM information_schema.columns WHERE table_name = 'app_accounts' ORDER BY ordinal_position;
SELECT count(*) AS mixed_case_columns
FROM information_schema.columns
WHERE table_name = 'app_accounts' AND column_name <> lower(column_name);

column_name
-------------
 id
 userId
 createdAt
 status
(4 rows)

 mixed_case_columns
--------------------
                  2
(1 row)

List information_schema.columns for the table (id, userId, createdAt, status), then count names where column_name <> lower(column_name); here mixed_case_columns = 2.

Remove the need for quoting. Rename the camelCase columns to lower_snake_case so an unquoted reference resolves naturally. This is the literal capture; the quick unblock if a rename is not yet possible is simply to quote the names.

ALTER TABLE app_accounts RENAME COLUMN "userId" TO user_id;
ALTER TABLE app_accounts RENAME COLUMN "createdAt" TO created_at;
SELECT 'unquoted_ok' AS result, id, user_id, status FROM app_accounts WHERE user_id = 42;

ALTER TABLE
ALTER TABLE
   result    | id | user_id | status
-------------+----+---------+--------
 unquoted_ok | 42 |      42 | active
(1 row)

ALTER TABLE app_accounts RENAME COLUMN "userId" TO user_id; RENAME COLUMN "createdAt" TO created_at; then SELECT ... WHERE user_id = 42 returns the row tagged unquoted_ok.

Confirm the healthy state: the old camelCase name no longer exists at all -- even the quoted spelling now errors (the expected proof the rename took effect) -- and the unquoted query returns user 42.

SELECT "userId" FROM app_accounts LIMIT 1;

ERROR:  42703: column "userId" does not exist
LINE 1: SELECT "userId" FROM app_accounts LIMIT 1;
               ^
HINT:  Perhaps you meant to reference the column "app_accounts.user_id".
LOCATION:  errorMissingColumn, parse_relation.c:3729

SELECT count(*) AS rows_for_user_42 FROM app_accounts WHERE user_id = 42;

rows_for_user_42
------------------
                1
(1 row)

SELECT "userId" FROM app_accounts now fails with 42703 and a HINT pointing at user_id (expected); then count(*) WHERE user_id = 42 returns 1.

📦 Version Matrix (PG 14--18)

Run the same break-and-fix on PostgreSQL 14, 15, 16, 17, and 18: an unquoted reference to a quoted camelCase column raises the identical 'column "userid" does not exist' on every version, and after renaming to lower_snake_case the unquoted query resolves identically. Identifier case-folding is uniform across all supported releases.

Frequently Asked Questions

References

• PostgreSQL: SQL Syntax -- Identifiers and Key Words (case folding, quoting)
• PostgreSQL: ALTER TABLE (RENAME COLUMN)
• PostgreSQL: information_schema.columns
• PostgreSQL Error Codes (Class 42 -- Syntax Error or Access Rule Violation)