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我正在尝试创建一个数据库，但它不起作用（应用程序强制停止）。我尝试检查日志猫，错误是“投影中的未知列”，它建议我检查 MyToDoContentProvider.java。我已经用我的 SQLite 语句检查了我的 MyToDoContentProvider.java，但我不知道它有什么问题。谁能帮我？tq..

这是我的 MyToDoContentProvider.java

package com.date.contentprovider;

import java.util.Arrays;
import java.util.HashSet;

import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.text.TextUtils;
import com.date.database.FirstClass;
import com.date.database.TodoDatabaseHelper;

public class MyTodoContentProvider extends ContentProvider {

// database
private TodoDatabaseHelper database;

// Used for the UriMacher
private static final int TODOS = 10;
private static final int TODO_ID = 20;

private static final String AUTHORITY = "com.date.contentprovider";

private static final String BASE_PATH = "todos";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY
  + "/" + BASE_PATH);

public static final String CONTENT_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE
  + "/todos";
public static final String CONTENT_ITEM_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE
  + "/todo";

private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static {
sURIMatcher.addURI(AUTHORITY, BASE_PATH, TODOS);
sURIMatcher.addURI(AUTHORITY, BASE_PATH + "/#", TODO_ID);
}

@Override
public boolean onCreate() {
database = new TodoDatabaseHelper(getContext());
return false;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection,
  String[] selectionArgs, String sortOrder) {

// Uisng SQLiteQueryBuilder instead of query() method
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

// Check if the caller has requested a column which does not exists
checkColumns(projection);

// Set the table
queryBuilder.setTables(FirstClass.TABLE_TODO);

int uriType = sURIMatcher.match(uri);
switch (uriType) {
case TODOS:
  break;
case TODO_ID:
  // Adding the ID to the original query
  queryBuilder.appendWhere(FirstClass.COLUMN_ID + "="
      + uri.getLastPathSegment());
  break;
default:
  throw new IllegalArgumentException("Unknown URI: " + uri);
}

SQLiteDatabase db = database.getWritableDatabase();
Cursor cursor = queryBuilder.query(db, projection, selection,
    selectionArgs, null, null, sortOrder);
// Make sure that potential listeners are getting notified
cursor.setNotificationUri(getContext().getContentResolver(), uri);

return cursor;
}

@Override
public String getType(Uri uri) {
return null;
}

@Override
public Uri insert(Uri uri, ContentValues values) {
int uriType = sURIMatcher.match(uri);
SQLiteDatabase sqlDB = database.getWritableDatabase();
int rowsDeleted = 0;
long id = 0;
switch (uriType) {
case TODOS:
  id = sqlDB.insert(FirstClass.TABLE_TODO, null, values);
  break;
default:
  throw new IllegalArgumentException("Unknown URI: " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return Uri.parse(BASE_PATH + "/" + id);
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
int uriType = sURIMatcher.match(uri);
SQLiteDatabase sqlDB = database.getWritableDatabase();
int rowsDeleted = 0;
switch (uriType) {
case TODOS:
  rowsDeleted = sqlDB.delete(FirstClass.TABLE_TODO, selection,
      selectionArgs);
  break;
case TODO_ID:
  String id = uri.getLastPathSegment();
  if (TextUtils.isEmpty(selection)) {
    rowsDeleted = sqlDB.delete(FirstClass.TABLE_TODO,
            FirstClass.COLUMN_ID + "=" + id, 
        null);
  } else {
    rowsDeleted = sqlDB.delete(FirstClass.TABLE_TODO,
            FirstClass.COLUMN_ID + "=" + id 
        + " and " + selection,
        selectionArgs);
  }
  break;
 default:
  throw new IllegalArgumentException("Unknown URI: " + uri);
 }
 getContext().getContentResolver().notifyChange(uri, null);
 return rowsDeleted;
}

@Override
public int update(Uri uri, ContentValues values, String selection,
  String[] selectionArgs) {

int uriType = sURIMatcher.match(uri);
SQLiteDatabase sqlDB = database.getWritableDatabase();
int rowsUpdated = 0;
switch (uriType) {
case TODOS:
  rowsUpdated = sqlDB.update(FirstClass.TABLE_TODO, 
      values, 
      selection,
      selectionArgs);
  break;
case TODO_ID:
  String id = uri.getLastPathSegment();
  if (TextUtils.isEmpty(selection)) {
    rowsUpdated = sqlDB.update(FirstClass.TABLE_TODO, 
        values,
        FirstClass.COLUMN_ID + "=" + id, 
        null);
  } else {
    rowsUpdated = sqlDB.update(FirstClass.TABLE_TODO, 
        values,
        FirstClass.COLUMN_ID + "=" + id 
        + " and " 
        + selection,
        selectionArgs);
  }
  break;
default:
  throw new IllegalArgumentException("Unknown URI: " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return rowsUpdated;
}

private void checkColumns(String[] projection) {
String[] available = { FirstClass.COLUMN_NAME,
        FirstClass.COLUMN_DESCRIPTION, FirstClass.COLUMN_CATEGORY,     FirstClass.COLUMN_TRIGGER,
        FirstClass.COLUMN_MON, FirstClass.COLUMN_TUE, FirstClass.COLUMN_WED, FirstClass.COLUMN_THU,
        FirstClass.COLUMN_FRI, FirstClass.COLUMN_SAT, FirstClass.COLUMN_SUN, FirstClass.COLUMN_DATE,
        FirstClass.COLUMN_TIME, FirstClass.COLUMN_LATITUDE, FirstClass.COLUMN_LONGITUDE, 
        FirstClass.COLUMN_STATUS };


if (projection != null) {
  HashSet<String> requestedColumns = new HashSet<String>(Arrays.asList(projection));
  HashSet<String> availableColumns = new HashSet<String>(Arrays.asList(available));
  // Check if all columns which are requested are available
  if (!availableColumns.containsAll(requestedColumns)) {
    throw new IllegalArgumentException("Unknown columns in projection");
  }
}

}

}

这是我的 FirstClass.java

package com.date.database;

import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class FirstClass {
 // Database table
  public static final String TABLE_TODO = "todo";
  public static final String COLUMN_ID = "_id";
  public static final String COLUMN_CATEGORY = "category";
  public static final String COLUMN_NAME = "name";
  public static final String COLUMN_DESCRIPTION = "description";
  public static final String COLUMN_TRIGGER ="trigger";
  public static final String COLUMN_MON = "mon";
  public static final String COLUMN_TUE = "tue";
  public static final String COLUMN_WED = "wed";
  public static final String COLUMN_THU = "thu";
  public static final String COLUMN_FRI ="fri";
  public static final String COLUMN_SAT = "sat";
  public static final String COLUMN_SUN = "sun";
  public static final String COLUMN_DATE = "date";
  public static final String COLUMN_TIME = "time";
  public static final String COLUMN_LATITUDE ="latitude";
  public static final String COLUMN_LONGITUDE= "longitude";
  public static final String COLUMN_STATUS = "status";



  // Database creation SQL statement
  private static final String DATABASE_CREATE = "create table " 
      + TABLE_TODO
      + "(" 
      + COLUMN_ID + " integer primary key autoincrement, " 
      + COLUMN_CATEGORY + " text not null, " 
      + COLUMN_NAME + " text not null," 
      + COLUMN_DESCRIPTION + " text not null," 
      + COLUMN_TRIGGER + " text not null ,"//'t', "
      + COLUMN_MON + " integer not null , "// == 1,"
      + COLUMN_TUE + " integer not null , "//== 2,"
      + COLUMN_WED + " integer not null , "// == 3,"
      + COLUMN_THU + " integer not null , "// == 4,"
      + COLUMN_FRI + " integer not null , "// == 5,"
      + COLUMN_SAT + " integer not null , "// == 6,"
      + COLUMN_SUN + " integer not null , "// == 0,"
      + COLUMN_DATE + " date not null,"
      + COLUMN_TIME + " time not null,"
      + COLUMN_LATITUDE + " decimal not null , "// ==0.00000000,"
      + COLUMN_LONGITUDE + " decimal not null , "// ==0.00000000,"
      + COLUMN_STATUS + " text not null  "// 'act' "
      + ");";

  public static void onCreate(SQLiteDatabase database) {
    database.execSQL(DATABASE_CREATE);

  }

  public static void onUpgrade(SQLiteDatabase database, int oldVersion,
      int newVersion) {
    Log.w(FirstClass.class.getName(), "Upgrading database from version "
        + oldVersion + " to " + newVersion
        + ", which will destroy all old data");
    database.execSQL("DROP TABLE IF EXISTS " + TABLE_TODO);
   // database.execSQL("INSERT INTO "+TABLE_TODO+" VALUES (null, datetime()) ");
    onCreate(database);
  }

}

这是我的 TodoDatabaseHelper.java

package com.date.database;


import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class TodoDatabaseHelper extends SQLiteOpenHelper {

  private static final String DATABASE_NAME = "todotable.db";
  private static final int DATABASE_VERSION = 1;
  final int oldVersion =1;
  final int newVersion =1;


  public TodoDatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }

  // Method is called during creation of the database
  @Override
  public void onCreate(SQLiteDatabase database) {
    FirstClass.onCreate(database);
  }

  // Method is called during an upgrade of the database,
  // e.g. if you increase the database version
  @Override
  public void onUpgrade(SQLiteDatabase database, int oldVersion,
      int newVersion) {
    FirstClass.onUpgrade(database, oldVersion, newVersion);
  }
}
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1 回答 1

1

检查您查询数据库的位置。您必须要求该特定表中不存在的列。

于 2012-12-16T14:30:01.613 回答