mysql数据库怎么删除重复项

SELECT DISTINCT * FROM table_name;

SELECT * FROM table_name GROUP BY column_name HAVING COUNT(*) > 1;

DELETE FROM table_name WHERE primary_key_column IN (
    SELECT primary_key_column FROM (
        SELECT primary_key_column FROM table_name GROUP BY column_name HAVING COUNT(*) > 1
    ) AS duplicate_rows
);

CREATE TABLE temp_table_name AS
SELECT DISTINCT * FROM table_name;

DELETE FROM table_name;

INSERT INTO table_name SELECT * FROM temp_table_name;

DROP TABLE temp_table_name;