【发布时间】:2011-06-04 02:39:44
【问题描述】:
所以我使用 SQLiteOpenHelper 创建了一个数据库,并尝试查询它。它返回光标,但是当我调用 moveToFirst() 时,它崩溃并出现错误 SQL Logic Error or Missing Database.
我按照这个网站的代码来创建和查询我的数据库:http://www.vogella.de/articles/AndroidSQLite/article.html
编辑:
我的数据库:
public class Database{
private static final String DATABASE_NAME = "MyDatabase";
private static final int DATABASE_VERSION = 1;
private static final String TABLE_NAME = "MyTable";
// Column Names
public static final String ID = "_id"; // INTEGER
public static final String NUMBER = "number"; // TEXT
private SQLiteDatabase database;
private DatabaseHelper mDatabaseOpenHelper;
public Database(Context context){
mDatabaseOpenHelper = new DatabaseHelper(context);
database = mDatabaseOpenHelper.getWritableDatabase();
}
public void close(){
database.close();
}
public long addNumber(String number){
ContentValues values = new ContentValues();
values.put(NUMBER, number);
return database.insert(TABLE_NAME, null, values);
}
public Cursor getNumber(String number){
String selection = NUMBER + " MATCH ?";
String[] selectionArgs = new String[] {number};
return database.query(TABLE_NAME, null, selection, selectionArgs, null, null, null);
}
private class DatabaseHelper extends SQLiteOpenHelper{
private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "(_id INTEGER PRIMARY KEY AUTOINCREMENT, " + NUMBER + " TEXT)";
public DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
}
}
这就是我的查询方式:
Database database = new Database(this);
Cursor cursor = database.getTrUpdate("1234");
if (cursor.moveToFirst()){
do{
int d = cursor.getInt(cursor.getColumnIndex(Database.ID));
} while(cursor.moveToNext());
}
【问题讨论】:
-
您能否也发布您的 DataBaseHelper 代码?