mysql - 溶解第二条选择语句

我得到以下查询，它也很好。

SELECT date, duration, educationDepartment, yearOfTraining, completedtasks
FROM programm_completedtask
WHERE date BETWEEN '2014-08-05' AND '2014-08-08'
  AND trainee_id =
    (SELECT id FROM programm_trainee WHERE username = 'Markus');

除了第二个select语句，还有其他可能要做的事情吗？我只想选择一次。

最佳答案

使用内连接...

SELECT p.date, p.duration, p.educationDepartment, p.yearOfTraining, p.completedtasks
FROM programm_completedtask as p
INNER JOIN programm_trainee as pt on p.trainee_id = pt.id AND  pt.username = 'Markus'
WHERE p.date BETWEEN '2014-08-05' AND '2014-08-08'

要么

SELECT p.date, p.duration, p.educationDepartment, p.yearOfTraining, p.completedtasks
FROM programm_completedtask as p
INNER JOIN programm_trainee as pt on p.trainee_id = pt.id
WHERE p.date BETWEEN '2014-08-05' AND '2014-08-08'
AND  pt.username = 'Markus'

关于mysql - 溶解第二条选择语句，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/25206295/