通过组获得第一个非空值

Question

我有下表

以下是我想要实现的结果

解释

我想按位置对数据进行分组，并获取列中可用的第一个非空值。例如，对于 locationcd 1300，列 A 将具有值John，列 B 将具有值John，列 C 将具有值Taylor和列 D 将具有值Brian。

我的解决方案

我做了一些不保证正确结果的事情。这是我的查询

select locationCd,
min([$1-$500]),
min([$501-$2500]) as '$501-$2500',
Min([$2501-$5000]) as '$2501-$5000',
min([$$5000 and above])  as '$$5000 and above'
from #tab
group by LocationCd 

请帮忙。

Answer 1

Select LocationId, MAX(Ty1.A) A
From #tabl T01
Outer Apply (Select Top 1 A From #tabl T1 Where T1.LocationId=T01.LocationId And T1.A Is Not Null) Ty1
Group By LocationId

这对你有帮助???

Answer 2

// Singelton class
public class MyComparator implements  Comparator<String> {

private static MyComparator myComparator = null;

private MyComparator() {}

@Override
public int compare(String a, String b) {
    return compareString(a,b);
}

public static int compareString(String a, String b) {
    if (a.length() > b.length())
        return -1;
    if (a.length() == b.length()) {
        if (a.compareTo(b) > 0)
            return -1;
        else if (a.compareTo(b) == 0)
            return 0;
    }

    return 1;
}

public static synchronized MyComparator getInstance() {
    if(myComparator==null) {
        myComparator = new MyComparator();
    }

    return myComparator;
}

}

Answer 3

试试这个。希望这有助于你...

select LocationCD,min(A),min(B),min(C),min(D)
from #tab
group by LocationCD

Answer 4

以下查询将提供所需的结果： -

select ROW_NUMBER() OVER ( partition by locationCd order by locationCd) RID,locationCd,A,B,C,D into #t1 from table_name

select locationcd,min(A) A,
(select B from #t1 b where b.locationcd=a.locationcd AND b.RID=3) B,
(select C from #t1 c where c.locationcd=a.locationcd AND c.RID=2) C,
(select D from #t1 d where d.locationcd=a.locationcd AND d.RID=1) D
from #t1 a
group by locationcd

drop table #t1

输出： -

 locationcd   A       B      C      D
 200        David   David  Detlef  Brian
 201        David   David  Detlef  Brian
 400        Walter  Brad   Detlef  Brian
 1200       David   David  Detlef  Brian
 1300       John    John   Taylor  Brian
 1400       Walter  Brad   Detlef  Brian

将table_name替换为必需的表