PostgreSQL Error 42703

SQLSTATE

42703

Condition name

undefined_column

Product

PostgreSQL

Versions

PostgreSQL 13 to 18 (examples run on PostgreSQL 18.6 in PGlite)

Category

Syntax & Names

Last reviewed

24 October 2026

What it means

SQLSTATE 42703 means a column name in the statement does not match any column of the tables in scope, usually because of case, a typo, a string written in double quotes, or an alias used where it is not visible.

PostgreSQL resolves every column name against the tables in the FROM clause (and, for INSERT and UPDATE targets, against the target table). If none has it, the statement fails with 42703 (undefined_column). Names follow the same rules as table names: unquoted names are folded to lower case, so a column created as "FirstName" is only found as "FirstName", and the message shows the folded name, firstname. When a column with a similar name exists, PostgreSQL adds a HINT such as Perhaps you meant to reference the column "customers.FirstName"., which usually is the answer.

Two other causes are easy to miss. Double quotes mark identifiers, so WHERE name = "Bob" looks for a column called Bob; strings take single quotes. And an output alias from the SELECT list can be used in ORDER BY and GROUP BY but not in WHERE or HAVING: WHERE annual > 1000 fails even though salary * 12 AS annual is in the same query. SQL Server functions written with bare date parts, such as dateadd(day, 1, now()), also fail here first, because day is read as a column name.

Common causes

• The column was created with a quoted mixed-case name ("FirstName") and is referenced unquoted.
• A typo, or a name from another environment or an old version of the schema (a migration that adds the column has not run).
• A string value written in double quotes instead of single quotes, so it is read as a column name.
• An output alias used in WHERE or HAVING, where it is not visible yet.
• The column belongs to a different table than the one the alias points at, or the right table is missing from FROM.
• INSERT or UPDATE names a column that the target table does not have, or UPDATE ... SET qualifies the column with the table name.
• SQL Server or MySQL functions with bare keywords such as day or month (dateadd, datediff), which PostgreSQL reads as column names.

Diagnose it

Read-only These queries only read the system catalogs (pg_catalog, information_schema) and statistics views such as pg_stat_activity and pg_locks. They do not change data, roles or settings, so they are safe to run first.

SELECT column_name, data_type
FROM information_schema.columns
WHERE table_schema = 'public'
  AND table_name = 'customers'
ORDER BY ordinal_position;

SELECT table_schema, table_name, column_name
FROM information_schema.columns
WHERE lower(column_name) = lower('firstname')
  AND table_schema NOT IN ('pg_catalog', 'information_schema')
ORDER BY 1, 2;

How to fix it

Each fix is labelled with what it changes. Try read-only checks and the least invasive fix first, and test changes outside production.

SELECT "FirstName" FROM customers;

-- or rename it once
ALTER TABLE customers RENAME COLUMN "FirstName" TO first_name;

SELECT * FROM customers WHERE last_name = 'Bob';

SELECT salary * 12 AS annual
FROM customers
WHERE salary * 12 > 1000;

-- or
SELECT *
FROM (SELECT id, salary * 12 AS annual FROM customers) AS t
WHERE annual > 1000;

SELECT now() + interval '1 day' AS tomorrow;

ALTER TABLE customers ADD COLUMN bonus numeric;

Examples

A quoted mixed-case column referenced without quotes

CREATE TABLE customers (id int, "FirstName" text, last_name text);

SELECT FirstName FROM customers;

ERROR:  column "firstname" does not exist
HINT:  Perhaps you meant to reference the column "customers.FirstName".

A string value in double quotes

CREATE TABLE customers (id int, first_name text, last_name text);

SELECT * FROM customers WHERE last_name = "Bob";

ERROR:  column "Bob" does not exist

A SELECT alias used in WHERE

CREATE TABLE customers (id int, salary numeric);

SELECT salary * 12 AS annual
FROM customers
WHERE annual > 1000;

ERROR:  column "annual" does not exist

Inserting into a column the table does not have

CREATE TABLE customers (id int, salary numeric);

INSERT INTO customers (id, bonus) VALUES (1, 5);

ERROR:  column "bonus" of relation "customers" does not exist

How to prevent it

Use lower case names with underscores for every column and never quote them, and turn off identifier quoting in ORMs and GUI tools that create tables. Keep application code and migrations in step, so code that reads a new column is deployed only after the migration that adds it.

Always use single quotes for strings, or better, parameters. Qualify columns with table aliases in multi-table queries, which also prevents 42702 ambiguous column errors.

Common questions

Learn more on CodeWithSQL

• SQL WHERE clause explained
• ORDER BY, GROUP BY and HAVING explained
• SQL Server to PostgreSQL

Official documentation

• PostgreSQL error codes (Appendix A)
• Identifiers and key words (case folding and quoting)
• SELECT (output names and where they can be used)
• Date/time functions and operators

Last technically reviewed 24 October 2026; examples and diagnostics run on PostgreSQL 18.6 (PGlite 0.5.11). SQL-level examples were run in PGlite (PostgreSQL compiled to WebAssembly); examples that need a running server are shown as documented in the PostgreSQL documentation.