Найдите дубликаты колонки MySQL
SELECT name, COUNT(*) c FROM table GROUP BY name HAVING c > 1;
Enthusiastic Elephant
SELECT name, COUNT(*) c FROM table GROUP BY name HAVING c > 1;SELECT col, COUNT(col) FROM table_name GROUP BY col HAVING COUNT(col) > 1;SELECT
col1, COUNT(col1),
col2, COUNT(col2)
FROM
table_name
GROUP BY
col1,
col2
HAVING
(COUNT(col1) > 1) AND
(COUNT(col2) > 1);