从SQLite获取所有行

Question

我一直试图从SQLite数据库获取所有行。但是，我只从下面的代码中得到最后一行。

文件选择器类：

public ArrayList<String> readFileFromSQLite() { 

    fileName = new ArrayList<String>(); 

    fileSQLiteAdapter = new FileSQLiteAdapter(FileChooser.this); 
    fileSQLiteAdapter.openToRead(); 
    cursor = fileSQLiteAdapter.queueAll(); 

    if (cursor != null) { 
    if (cursor.moveToFirst()) { 
     do { 
     fileName.add(cursor.getString(cursor.getColumnIndex(FileSQLiteAdapter.KEY_CONTENT1))); 
     } while (cursor.moveToNext()); 

    } 
    cursor.close(); 
    } 

    fileSQLiteAdapter.close(); 
    return fileName; 
} 

FileSQLiteAdapter类：

public Cursor queueAll() { 
    String[] columns = new String[] { KEY_ID, KEY_CONTENT1 }; 

    Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns, null, 
       null, null, null, null); 
    return cursor; 
} 

请告诉我哪里是我的不正确。欣赏。

Answer 1

尝试：

Cursor cursor = db.rawQuery("select * from table",null); 

和List<String>：

if (cursor.moveToFirst()) { 
    while (!cursor.isAfterLast()) { 
    String name = cursor.getString(cursor.getColumnIndex(countyname)); 

    list.add(name); 
    cursor.moveToNext(); 
    } 
} 

Answer 2

我一直在寻找到同样的问题！我认为你的问题与你在哪里识别你用来填充你返回的ArrayList的变量有关。如果您在循环中定义它，那么它将始终引用数据库中表中的最后一行。为了避免这种情况，你必须确定它的外循环：

String name; 
if (cursor.moveToFirst()) { 

     while (cursor.isAfterLast() == false) { 
      name = cursor.getString(cursor 
        .getColumnIndex(countyname)); 

      list.add(name); 
      cursor.moveToNext(); 
     } 
} 

Answer 3

这几乎是相同的解决方案为别人，但我想这可能是很好看实现相同的结果的不同方式，解释一下：

大概你有表名字符串变量在你调用DBHandler的时候被初始化，所以它会是这样的;

private static final String MYDATABASE_TABLE = "anyTableName"; 

然后，无论您尝试检索所有表格行，

SQLiteDatabase db = this.getReadableDatabase(); 
Cursor cursor = db.rawQuery("select * from " + MYDATABASE_TABLE, null); 

List<String> fileName = new ArrayList<>(); 
if (cursor.moveToFirst()){ 
    fileName.add(cursor.getString(cursor.getColumnIndex(COLUMN_NAME))); 
    while(cursor.moveToNext()){ 
     fileName.add(cursor.getString(cursor.getColumnIndex(COLUMN_NAME))); 
    } 
} 
cursor.close(); 
db.close(); 

老实说，大概有这样做的方法很多，

Answer 4

更新queueAll()方法如下：

更新readFileFromSQLite()方法如下：

public ArrayList<String> readFileFromSQLite() { 

    fileName = new ArrayList<String>(); 

    fileSQLiteAdapter = new FileSQLiteAdapter(FileChooser.this); 
    fileSQLiteAdapter.openToRead(); 

    cursor = fileSQLiteAdapter.queueAll(); 

    if (cursor != null) { 
     if (cursor.moveToFirst()) { 
      do 
      { 
       String name = cursor.getString(cursor.getColumnIndex(FileSQLiteAdapter.KEY_CONTENT1)); 
       fileName.add(name); 
      } while (cursor.moveToNext()); 
     } 
     cursor.close(); 
    } 

    fileSQLiteAdapter.close(); 

    return fileName; 
} 

Answer 5

其他答案使用rawQuery。 documentation对于SQLiteDatabase表示，您可以将null传递给查询的selection参数以获取所有行。

selection传递null将返回给定表的所有行。

例

SQLiteDatabase db = mHelper.getReadableDatabase(); 
String[] columns = { 
     MyDatabaseHelper.COLUMN_1, 
     MyDatabaseHelper.COLUMN_2, 
     MyDatabaseHelper.COLUMN_3}; 
String selection = null; // this will select all rows 
Cursor cursor = db.query(MyDatabaseHelper.MY_TABLE, columns, selection, 
     null, null, null, null, null); 

Answer 6

Cursor cursor = myDb.viewData(); 

     if (cursor.moveToFirst()){ 
       do { 
       String itemname=cursor.getString(cursor.getColumnIndex(myDb.col_2)); 
       String price=cursor.getString(cursor.getColumnIndex(myDb.col_3)); 
       String quantity=cursor.getString(cursor.getColumnIndex(myDb.col_4)); 
       String table_no=cursor.getString(cursor.getColumnIndex(myDb.col_5)); 

       }while (cursor.moveToNext()); 

       } 

       cursor.requery();