mysql 筛选重复数据

SELECT DISTINCT column1, column2, ...
FROM table_name;

SELECT DISTINCT name, email
FROM users;

SELECT column1, column2, ...
FROM table_name
GROUP BY column1, column2, ...
HAVING COUNT(*) > 1;

SELECT name, email
FROM users
GROUP BY name, email
HAVING COUNT(*) > 1;

SELECT t1.*
FROM table_name t1
JOIN (
    SELECT column1, column2, ...
    FROM table_name
    GROUP BY column1, column2, ...
    HAVING COUNT(*) > 1
) t2
ON t1.column1 = t2.column1 AND t1.column2 = t2.column2;

SELECT t1.*
FROM users t1
JOIN (
    SELECT name, email
    FROM users
    GROUP BY name, email
    HAVING COUNT(*) > 1
) t2
ON t1.name = t2.name AND t1.email = t2.email;

DELETE t1 FROM users t1
JOIN (
    SELECT name, email
    FROM users
    GROUP BY name, email
    HAVING COUNT(*) > 1
) t2
ON t1.name = t2.name AND t1.email = t2.email
WHERE t1.id NOT IN (
    SELECT MIN(id)
    FROM users
    GROUP BY name, email
);