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我正在创建一个应用程序，我在其中从不同的活动调用我的数据库，但我不断从数据库方面收到各种错误。起初，我得到一个

“SQLiteException 没有这样的数据”

当我删除我的应用程序并重新安装它时，现在

“android.database.sqlite.SQLiteConstraintException：错误代码 19：约束失败”

我不知道该怎么办了。在创建数据库方面经历了很多不同的例子，但我不知道我是否遗漏了什么？..这是我的数据库端代码：

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;


public class DBAdapter {

    private static final String DATABASE_NAME = "MemoData.db";
    private static final int DATABASE_VERSION = 1;
    public static final String DATABASE_TABLE = "Memo";

    public static final String KEY_ID = "_id";
    public static final String NAME = "Title";
    public static final String START_DATE = "start_date";
    public static final String END_DATE = "end_date";
    public static final String NOTES = "notes";

    private static final String TAG = "DBAdapter";

    private static final String DATABASE_CREATE = "create table Memo (_id integer primary key autoincrement,"   
        + "Title text not null, start_date text not null,"
        + "end_date text not null, "
        + "notes text not null);";

    private final Context context;   
    private DBHelper dbhelper;
    private SQLiteDatabase db;

    public DBAdapter(Context context) {
        this.context = context;
        dbhelper = new DBHelper(context);
    }

    private static class DBHelper extends SQLiteOpenHelper {

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

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(DATABASE_CREATE);
        }


        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG,"upgrading Database from version"+ oldVersion+ "to"
                    +newVersion+ "which oold data will be lost");
            db.execSQL("DROP TABLE IF EXITS Memo");
            onCreate(db);
        }
    }

    public DBAdapter open()throws SQLException {
        db = dbhelper.getWritableDatabase();
        return this;
    }

    public void close(){
        dbhelper.close();
    }

  public long createItem(String Title, String start_date,String end_date,String notes){
             open();
            ContentValues initialValues = new ContentValues();
            initialValues.put(NAME, Title);
            initialValues.put(START_DATE, start_date);
            initialValues.put(END_DATE, end_date);
            initialValues.put(NOTES, notes);

            return db.insert(DATABASE_TABLE, null, initialValues);
            }

      public Cursor retrieveItems(){
            SQLiteDatabase db = dbhelper.getWritableDatabase();
            String[] resultColumns = new String[] {NAME,START_DATE,END_DATE,NOTES };     
     Cursor cursor = db.query(DATABASE_TABLE, resultColumns, null, null, null, null, null);

            Integer cindex = cursor.getColumnIndex("Title");
            String result = "Result = ";

            if(cursor.moveToFirst()){
                do {
                    result += cursor.getString(cindex)+ "-";
                }while(cursor.moveToNext());
            }
            return cursor;
        }
}

这是主要的错误输出：

08-23 22:38:17.104: ERROR/Database(775): Error inserting notes=Notes: end_date=Due Date: Title=Name of Item: start_date=Start Date:
08-23 22:38:17.104:ERROR/Database(775): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed

08-23 22:38:17.104: ERROR/Database(775):at android.database.sqlite.SQLiteStatement.native_execute(Native Method)

08-23 22:38:17.104: ERROR/Database(775):at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:66)

08-23 22:38:17.104: ERROR/Database(775):at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1313)

08-23 22:38:17.104: ERROR/Database(775):at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1173)

08-23 22:38:17.104: ERROR/Database(775):at com.Memo.DBAdapter.createItem(DBAdapter.java:94)

08-23 22:38:17.104: ERROR/Database(775):at com.Memo.NewItem.save(NewItem.java:365)
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1 回答 1

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在您的 onUpgrade 事件中，您将删除表 DATABASE_NAME，但不应该是 DATABASE_TABLE 吗？

没有什么（除此之外）对我产生影响，当您实例化 DBAdapter 对象时，您是否收到此错误？错误发生在 onCreate 事件还是其他地方？

于 2010-08-23T21:38:50.027 回答