42703 — Undefined Column

Nguyên nhân gây ra lỗi này

The column name is misspelled, not yet added, or the table alias is wrong.

Cách sửa

Check the column name for typos. Verify the column exists with \d tablename. Ensure the correct table alias is used.

-- undefined_column
SELECT nonexistent_col FROM users;
-- Fix: check column names
SELECT column_name FROM information_schema.columns
  WHERE table_name = 'users';