有一个数据库表格，包含了roleA, roleB两个字段，写了一个SQL，相同的roleA,但是roleB不一样，同时roleb不一样的数量要大于2 ；
SELECT roleA
FROM your_table_name
GROUP BY roleA
HAVING COUNT(DISTINCT roleB) > 2;
SELECT roleA, roleB
FROM your_table_name
WHERE roleA IN (
SELECT roleA
FROM your_table_name
GROUP BY roleA
HAVING COUNT(DISTINCT roleB) > 2
);
