我想从数据库中读取值并将其转换为字符串数组。
strQ = "SELECT * FROM Courses"
cmd = New SqlCommand(strQ, conn)
da = New SqlDataAdapter(cmd)
ds = New DataSet
da.Fill(ds, "Courses")
Dim i As Integer = 0
Dim j As Integer = 0
For i = 0 To ds.Tables(0).Columns.Count - 1
Me.ListView1.Columns.Add(ds.Tables(0).Columns(i).ColumnName.ToString())
Next
For i = 0 To ds.Tables(0).Rows.Count - 1
For j = 0 To ds.Tables(0).Columns.Count - 1
itemcol(j) = ds.Tables(0).Rows(i)(j).ToString()
Next
Dim lvi As New ListViewItem(itemcol)
Me.ListView1.Items.Add(lvi)
Next
我想将其转换为数组格式。
从评论中编辑:基本上我们正在处理课程和学生人数。这些数字是参加课程的学生ID。以下是一些示例数据:
jb(0) = {1,2,3,4,5} 'CIT121
jb(1) = {1,2,6,7,8} 'CIT141
jb(2) = {6,7,8,15,16} 'CIT202
jb(3) = {4,10,11} 'CIT203
答案 0 :(得分:0)
您可以使用提到的代码
String id1 = "id1";
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("messages");
ref.orderByKey().startAt(id1).endAt(id1 + "\uf8ff").addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snap : dataSnapshot.getChildren()) {
Log.d("SNAP", snap.getValue(String.class));
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});