我执行了一个从数据库中检索项目列表的查询:
CREATE PROCEDURE dbo.GetSubjects(@DayComing varchar(10) , @UserId varchar(3))
AS
IF EXISTS(
SELECT Std_ID
FROM Student
WHERE Std_ID = @UserID)
BEGIN
SELECT TimeTable.Ttb_Subject
FROM Student INNER JOIN
我的代码中有一些部分如下所示:
A, B and C extend D
public ArrayList<A> getA() {
ArrayList<A> allElements = new ArrayList<A>();
for (D el : listOfDs) {
if (el instanceof A) {
allElements.add((A) el);
}
}
return allElements;
}
public ArrayList<B>