我有一个活动，我在其中将值插入sqlite表，然后查询表以获取值。
活动：
public class TableActivity extends Activity {
TableLayout follow_up_table;
TableRow followup_tr_data;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_table);
follow_up_table=(TableLayout) findViewById(R.id.follow_up_table);
//---------------Essay Title Table Header-----------------------------------------------
TableRow essay_title_tr_head = new TableRow(this);
essay_title_tr_head.setId(10);
essay_title_tr_head.setBackgroundResource(R.drawable.list_header);
essay_title_tr_head.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
TextView label_essay_title = new TextView(this);
label_essay_title.setId(20);
label_essay_title.setText("Time");
label_essay_title.setTextColor(Color.WHITE);
label_essay_title.setPadding(5,5,5,5);
essay_title_tr_head.addView(label_essay_title);// add the column to the table row here
label_essay_title.setTextSize(12);
TextView label_description = new TextView(this);
label_description.setId(20);
label_description.setText("Student Name");
label_description.setTextColor(Color.WHITE);
label_description.setPadding(5,5,5,5);
essay_title_tr_head.addView(label_description);// add the column to the table row here
label_description.setTextSize(12);
follow_up_table.addView(essay_title_tr_head, new TableLayout.LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
//---------------Essay Title Table Header-----------------------------------------------
//getTime();
// database handler
insertData("Morning", "2013-04-23 10:00:00", "Suresh Kumar");
insertData("Morning", "2013-04-23 11:30:00", "Pravat Das");
insertData("Evening", "2013-04-23 16:16:00", "Namita Roy");
insertData("Evening", "2013-04-23 17:30:00", "Rakesh Mitra");
insertData("After noon", "2013-04-23 10:00:00", "Anil Sarma");
getTime();
}
public void getTime()
{
// database handler
// database handler
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
// Spinner Drop down elements
List<String> lables = db.getTime();
Iterator itr = lables.iterator();
while(itr.hasNext())
{
System.out.println(itr.next());
}
}
//method to insert data into local database
public void insertData(String timeName, String time, String studentName)
{
DatabaseHandler db = new DatabaseHandler(TableActivity.this);
ContentValues values = new ContentValues();
//db.createDataBase();
values.put("timeName",timeName);
values.put("time",time);
values.put("studentName",studentName);
db.insertValues(timeName, time, studentName);
db.close();
}
}
数据库帮助程序类：
public class DatabaseHandler extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "counselor";
// Labels table name
private static final String TABLE_LABELS = "follow_up";
// Labels Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_time_name = "time_name";
private static final String KEY_time = "time";
private static final String KEY_student_name = "student_name";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
// Category table create query
String CREATE_CATEGORIES_TABLE = "CREATE TABLE follow_up (_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , time_name VARCHAR, time DATETIME, student_name VARCHAR)";
db.execSQL(CREATE_CATEGORIES_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
// Create tables again
onCreate(db);
}
public void insertValues(String timeName, String time, String studentName)
{
SQLiteDatabase db = this.getWritableDatabase();
String sql = "INSERT INTO follow_up ( time_name, time, student_name) VALUES ('"+timeName+"', '"+time+"', '"+studentName+"')";
Cursor cursor = db.rawQuery(sql, null); //<< execute here
cursor.moveToFirst();
db.close();
}
//
// /**
// * Getting all labels
// * returns list of labels
// * */
public List<String> getTime(){
List<String> labels = new ArrayList<String>();
// Select All Query
String selectQuery = "SELECT time_name FROM follow_up ORDER BY time";
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(1));
} while (cursor.moveToNext());
}
// closing connection
cursor.close();
db.close();
// returning lables
return labels;
}
}
logcat中的错误：
04-24 09:21:18.187: D/dalvikvm(1260): GC_FOR_ALLOC freed 66K, 7% free 2561K/2748K, paused 169ms, total 183ms
04-24 09:21:18.207: I/dalvikvm-heap(1260): Grow heap (frag case) to 3.222MB for 635812-byte allocation
04-24 09:21:18.328: D/dalvikvm(1260): GC_FOR_ALLOC freed 2K, 6% free 3179K/3372K, paused 116ms, total 116ms
04-24 09:21:18.467: D/dalvikvm(1260): GC_CONCURRENT freed <1K, 6% free 3190K/3372K, paused 9ms+27ms, total 141ms
04-24 09:21:19.167: E/CursorWindow(1260): Failed to read row 0, column 1 from a CursorWindow which has 5 rows, 1 columns.
04-24 09:21:19.167: D/AndroidRuntime(1260): Shutting down VM
04-24 09:21:19.167: W/dalvikvm(1260): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
04-24 09:21:19.197: E/AndroidRuntime(1260): FATAL EXCEPTION: main
04-24 09:21:19.197: E/AndroidRuntime(1260): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ica.dynamictable/com.ica.dynamictable.TableActivity}: java.lang.IllegalStateException: Couldn't read row 0, col 1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.os.Handler.dispatchMessage(Handler.java:99)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.os.Looper.loop(Looper.java:137)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-24 09:21:19.197: E/AndroidRuntime(1260): at java.lang.reflect.Method.invokeNative(Native Method)
04-24 09:21:19.197: E/AndroidRuntime(1260): at java.lang.reflect.Method.invoke(Method.java:511)
04-24 09:21:19.197: E/AndroidRuntime(1260): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-24 09:21:19.197: E/AndroidRuntime(1260): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-24 09:21:19.197: E/AndroidRuntime(1260): at dalvik.system.NativeStart.main(Native Method)
04-24 09:21:19.197: E/AndroidRuntime(1260): Caused by: java.lang.IllegalStateException: Couldn't read row 0, col 1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.database.CursorWindow.nativeGetString(Native Method)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.database.CursorWindow.getString(CursorWindow.java:434)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:51)
04-24 09:21:19.197: E/AndroidRuntime(1260): at com.ica.commons.DatabaseHandler.getTime(DatabaseHandler.java:77)
04-24 09:21:19.197: E/AndroidRuntime(1260): at com.ica.dynamictable.TableActivity.getTime(TableActivity.java:83)
04-24 09:21:19.197: E/AndroidRuntime(1260): at com.ica.dynamictable.TableActivity.onCreate(TableActivity.java:73)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.Activity.performCreate(Activity.java:5104)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-24 09:21:19.197: E/AndroidRuntime(1260): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
04-24 09:21:19.197: E/AndroidRuntime(1260): ... 11 more
实际上我要做的是将所有time_name放入一个列表中，以便我可以使用它来填充表格。
我哪里错了？
答案 0 :(得分：2)
在您的DBHelper getTime()方法中，您使用查询只获取一行。稍后在该方法中，您使用的是labels.add(cursor.getString(1));
您应该使用labels.add(cursor.getString(0));，因为Cursor
答案 1 :(得分：1)
cursor.getString(1)应为cursor.getString(0)，因为在查询"SELECT time_name FROM follow_up ORDER BY time";中，您只能在time_name 0获得一个数据，即cursor.getString(0) p>
答案 2 :(得分：0)
SELECT time_name FROM follow_up ORDER BY time
只包含1列。因此它的索引是0.你可以用
访问它labels.add(cursor.getString(0));
或者，更干净：
int index = cursor.getColumnIndex("time_name");
和
labels.add(cursor.getString(index));
此外，我应该补充一点，if ... do ... while可以替换为单个while(cursor.moveToNext())块，因为新创建的光标的位置始终在第一个之前，使得第一个moveToNext与moveToFirst