Поиск дубликатов значений столбцов в таблице с SQL
SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING COUNT(*) > 1
Cucumberman
SELECT username, email, COUNT(*)
FROM users
GROUP BY username, email
HAVING COUNT(*) > 1
SELECT name, COUNT(email)
FROM users
GROUP BY email
HAVING COUNT(email) > 1• SELECT first_name, COUNT (first_name) FROM employees
GROUP BY first_name
HAVING (COUNT(first_name) > 1);SELECT columnName, COUNT(columnName)
FROM tableName
GROUP BY columnName
HAVING COUNT(columnName)>1