因為時間有限先記錄一下簡單的幾個寫法，今天在項目中嘗試一下，后續補充。
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主要疑惑的是子查詢先記錄一下：
example：
QDepartment department = QDepartment.department;
QDepartment d = new QDepartment("d"); query.from(department) .where(department.employees.size().eq( new JPASubQuery().from(d).unique(d.employees.size().max()) )).list(department);
QEmployee employee = QEmployee.employee;
QEmployee e = new QEmployee("e"); query.from(employee) .where(employee.weeklyhours.gt( new JPASubQuery().from(employee.department.employees, e) .where(e.manager.eq(employee.manager)) .unique(e.weeklyhours.avg()) )).list(employee);