What is the method for removing duplicate data in MySQL?

In MySQL, you can utilize the following method to eliminate duplicate data:

  1. By using the DISTINCT keyword: Using the SELECT DISTINCT statement can eliminate duplicate rows in the result set.
SELECT DISTINCT column1, column2 FROM table_name;
  1. By using the GROUP BY clause, you can group the results set and then use aggregate functions to eliminate duplicate data.
SELECT column1, column2 FROM table_name GROUP BY column1, column2;
  1. Use a subquery: Take the data that needs to be deduplicated as a subquery, and then remove duplicate data through the main query.
SELECT column1, column2 FROM (SELECT DISTINCT column1, column2 FROM table_name) AS subquery;
  1. Use a temporary table: Insert the data that needs to be deduplicated into a temporary table, and then retrieve the deduplicated data from the temporary table.
CREATE TEMPORARY TABLE temp_table AS SELECT DISTINCT column1, column2 FROM table_name;
SELECT * FROM temp_table;

Here are some common methods that can be used to eliminate duplicate data, depending on the specific situation.

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