How to Delete Duplicate Records Without a Primary Key in SQL

Learn the best method to delete duplicate records without a primary key using temporary tables in SQL.

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To delete duplicate records without a primary key, use a temporary table: `CREATE TABLE temp_table AS SELECT DISTINCT FROM original_table; DELETE FROM original_table; INSERT INTO original_table SELECT FROM temp_table;` Ensure to review your data after the process.

FAQs & Answers

  1. What is the best way to delete duplicates if there is no primary key? Using a temporary table with SELECT DISTINCT to isolate unique records, then replacing the original table is an effective method.
  2. Can I delete duplicate records without creating a new table? Yes, but it is riskier; using temporary tables ensures data integrity during the duplicates removal process.
  3. How do I verify duplicate removal after the operation? You should query the table using COUNT and GROUP BY clauses to check for any remaining duplicates.

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