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因此，每次我在位于 AddContacts 类中的 EditText 字段中输入数据时，我的对话框都会说我已经成功添加了信息，但是在日志 cat 中它说没有这样的表：contactsTable。我认为错误在我的数据库类中的 onCreate 和 onUpdate 方法中，但我不知道该怎么做

代码：

package com.example.myfirstapp;

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;


public class DatabaseTable {
private static final String TAG = "ContactsDatabase";

//The columns we'll include in the contacts table
public static final String COL_ID = "ID";
public static final String COL_NAME = "NAME";
public static final String COL_EMAIL = "EMAIL";

private static final String DATABASE_NAME = "CONTACT";
private static final String DATABASE_TABLE = "contactsTable";
private static final int DATABASE_VERSION = 1;
private Context ourContext;
private DbHelper DBHelper;
private SQLiteDatabase db;
private static final String DATABASE_CREATE = 
        "CREATE TABLE " + DATABASE_TABLE + " (" +
         COL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
         COL_NAME + " TEXT NOT NULL, " + 
         COL_EMAIL + " TEXT NOT NULL);";

    private static class DbHelper extends SQLiteOpenHelper {

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

        public void onCreate(SQLiteDatabase db) {
            try {
                db.execSQL(DATABASE_CREATE);
            } catch (SQLException e) {
                e.printStackTrace();
            }
    }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
            onCreate(db);
        }
    }

        public DatabaseTable(Context context) {
            ourContext = context;
        }

        public DatabaseTable open() throws SQLException {
            DBHelper = new DbHelper(ourContext);
            db = DBHelper.getWritableDatabase();
            return this;
        }

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

        public long insertContact(String name, String email) {
            ContentValues initialValues = new ContentValues();
            initialValues.put(COL_NAME, name);
            initialValues.put(COL_EMAIL, email);
            return db.insert(DATABASE_TABLE, null, initialValues);
        }

        public void deleteRecord(long rowId)
        {
            db.delete(DATABASE_TABLE, COL_ID + "=" + rowId, null);
        }

        public Cursor getAllRecords() {
            return db.query(DATABASE_TABLE, new String[] {COL_ID, COL_NAME, COL_EMAIL}, null, 
                    null, null, null, null);
        }

        public Cursor getRecord(long rowId) throws SQLException {

            Cursor cursor = db.query(true, DATABASE_TABLE, new String[] {COL_ID, COL_NAME,
                    COL_EMAIL}, COL_ID + "=" + rowId, null, null, null, null, null);

            if (cursor != null)
                cursor.moveToFirst();

            return cursor;
            }

        public boolean updateRecord(long rowId, String name, String email) {
            ContentValues content = new ContentValues();
            content.put(COL_NAME, name);
            content.put(COL_EMAIL, email);
            return db.update(DATABASE_TABLE, content, COL_ID + "=" + rowId, null) > 0;
        }

}

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1 回答 1

3

你DATABASE_TABLE在运行你的应用程序至少一次后改变了吗？如果是这样，您需要更新 SQLite 架构，最简单的方法是 make DATABASE_VERSION = 2;。另外Android对主键很讲究，应该COL_ID改成"_id".

DATABASE_VERSION将来，每次更改CREATE_TABLE语句时都必须递增。否则 SQLite 将没有当前信息。

于 2012-12-26T18:35:55.033 回答