sqlite 无重复随机()查询

sqxo8psd 于 2023-10-23 发布在 SQLite

关注(0)|答案(2)|浏览(139)

我需要显示3从SQLite数据库随机图像水平。由于不可能创建一个水平的ListView，我在一个水平方向的LinearLayout中创建了3个相邻的ListView：

final ListView g = (ListView)findViewById(R.id.lstText1);
final ListView h = (ListView)findViewById(R.id.lstText2);
final ListView i = (ListView)findViewById(R.id.lstText3);

g.setOnItemClickListener(this);
h.setOnItemClickListener(this);
i.setOnItemClickListener(this);
// Set the adapter to our custom adapter (below)

g.setAdapter(new MySimpleCursorAdapter(this, R.layout.toplist,
    managedQuery(Uri.withAppendedPath(Provider.CONTENT_URI,
    Database.Project.NAME), new String[] { BaseColumns._ID,
    Database.Project.C_SMALLIMAGE}, null, null, "RANDOM() LIMIT 1"),
    new String[] { Database.Project.C_SMALLIMAGE }, new int[] {R.id.image1}));

h.setAdapter(new MySimpleCursorAdapter(this, R.layout.toplist,
    managedQuery(Uri.withAppendedPath(Provider.CONTENT_URI,
    Database.Project.NAME), new String[] { BaseColumns._ID,
    Database.Project.C_SMALLIMAGE}, null, null, "RANDOM() LIMIT 1"),
    new String[] { Database.Project.C_SMALLIMAGE }, new int[] {R.id.image1}));

i.setAdapter(new MySimpleCursorAdapter(this, R.layout.toplist,
    managedQuery(Uri.withAppendedPath(Provider.CONTENT_URI,
    Database.Project.NAME), new String[] { BaseColumns._ID,
    Database.Project.C_SMALLIMAGE}, null, null, "RANDOM() LIMIT 1"),
    new String[] { Database.Project.C_SMALLIMAGE }, new int[] {R.id.image1}));

一切正常，除了随机显示的图像应该彼此不同。由于我使用3个不同的列表视图，有时他们显示相同的随机图像。如何解决我的问题？修改"RANDOM() LIMIT 1"

sqlite

来源：https://stackoverflow.com/questions/6304875/unrepeated-random-query

2条答案

按热度按时间

drkbr07n1#

FSM保存我们.你还在这里
对于单个项目，ListView是一个坏主意
只需将3个ImagesView放在布局中，然后执行以下操作

final ImageView[] images = new ImageView[3];
ImageLoader loader = new ImageLoader(this);

images[0] = (ImageView)findViewById(R.id.imageView1);
images[1] = (ImageView)findViewById(R.id.imageView2);
images[2] = (ImageView)findViewById(R.id.imageView3);

int counter = 0;

    Cursor c = managedQuery(Uri.withAppendedPath(Provider.CONTENT_URI,
                    Database.Project.NAME), new String[] { BaseColumns._ID,
                    Database.Project.C_SMALLIMAGE}, null, null, "RANDOM() LIMIT 3");
  if(c!=null && c.moveToFirst()){
     do{
       String url = c.getString(1);
       images[counter].setTag(url);
       loader.DisplayImage(url, this, images[counter]);
       counter++;
     }while(c.moveToNext());
  }

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dl5txlt92#

获取行数，在客户端从0到rowcount-1范围内选择随机数，然后使用LIMIT选择第n行。

赞(0）回复(0）举报 2023-10-23