在MySQL中选择多行的特定值和条件依赖项

Question

 var processId = process.Id;
        process = null;
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
        process = System.Diagnostics.Process.GetProcessById(processId);

我们有这样的数据，我们需要选择具有certificate_id 2和3的coach_id。所以，在这里我需要选择coach_id = 7.

Answer 1

SELECT coach_id
FROM your_table 
WHERE certificate_id IN (2,3)
GROUP BY coach_id
HAVING COUNT(*)>=2;