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Description

This error indicates that a SQL query references a column name that does not exist in the specified table or view. It's a common syntax error that prevents the database from executing the statement, often due to a typo or a misunderstanding of the database schema.

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Error Message

undefined column

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Known Causes

4 known causes

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Typographical Error in Column Name

A simple spelling mistake or incorrect casing in the column name within your SQL query.

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Non-Existent Column

The referenced column was never created in the table, or it has been dropped from the schema.

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Incorrect Table Reference or Alias

The column exists but is being referenced from the wrong table or an incorrect alias in a multi-table query.

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Case Sensitivity Mismatch

PostgreSQL identifiers can be case-sensitive if quoted, or if the system uses a case-sensitive collation, leading to a mismatch.

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Solutions

5 solutions available

1. Verify Column Name easy

Check column spelling and case

1

List table columns

\d your_table
-- or
SELECT column_name FROM information_schema.columns
WHERE table_name = 'your_table';

2

Search for similar column names

SELECT column_name FROM information_schema.columns
WHERE table_name = 'users' AND column_name LIKE '%name%';

2. Fix Case Sensitivity easy

PostgreSQL lowercases unquoted identifiers

1

Use quotes for mixed-case columns

-- If column is "firstName" (with quotes during creation):
SELECT "firstName" FROM users;

-- Not:
SELECT firstName FROM users;  -- becomes 'firstname'

3. Use Table Alias Correctly easy

Reference columns with proper table prefix

1

Check alias usage in JOINs

-- Wrong:
SELECT name FROM users u JOIN orders o ON u.id = user_id

-- Right:
SELECT u.name FROM users u JOIN orders o ON u.id = o.user_id

4. Add Missing Column medium

Create the column if it should exist

1

Add column to table

ALTER TABLE users ADD COLUMN phone VARCHAR(20);

5. Fix String Quoting easy

Use single quotes for strings, double for identifiers

1

Understand PostgreSQL quoting

-- Double quotes = identifier (table/column name)
-- Single quotes = string value

-- Wrong (treats name as identifier):
SELECT * FROM users WHERE name = "John"

-- Right:
SELECT * FROM users WHERE name = 'John'

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Related Errors

5 related errors

PostgreSQL Error 42703: Undefined Column Reference