java - Android 表未创建

Question

我正在尝试为我的 Android 应用程序创建一个 SQLite DB。我有所有代码，但我在 logcat 中收到错误，指出没有这样的表。我认为我有正确的代码，但如果您能看一下我是否遗漏了某些内容，我将不胜感激。

package com.example.rory.dbtest;


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 {
public static final String KEY_ROWID = "id";
public static final String KEY_ITEM = "item";
public static final String KEY_LITRES = "litres";
//public static final String KEY_COURSE = "course";
//public static final String KEY_NOTES = "notes";
private static final String TAG = "DBAdapter";

private static final String DATABASE_NAME = "DripDrop";
private static final String DATABASE_TABLE = "table1";
private static final int DATABASE_VERSION = 1;

private static final String DATABASE_CREATE =
        "create table if not exists assignments (id integer primary key autoincrement, "
                + "item VARCHAR not null, litres date );";

private final Context context;

private DatabaseHelper DBHelper;
private SQLiteDatabase db;

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

private static class DatabaseHelper extends SQLiteOpenHelper
{
    DatabaseHelper(Context context)
    {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    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)
    {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS contacts");
        onCreate(db);
    }
}

//---opens the database---
public DBAdapter open() throws SQLException
{
    db = DBHelper.getWritableDatabase();
    return this;
}

//---closes the database---
public void close()
{
    DBHelper.close();
}

//---insert a record into the database---
public long insertRecord(String item, String litres)
{
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_ITEM, item);
    initialValues.put(KEY_LITRES, litres);
    //initialValues.put(KEY_COURSE, course);
    //initialValues.put(KEY_NOTES, notes);
    return db.insert(DATABASE_TABLE, null, initialValues);
}

//---deletes a particular record---
public boolean deleteContact(long rowId)
{
    return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}

//---retrieves all the records---
public Cursor getAllRecords()
{
    return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_ITEM,
            KEY_LITRES}, null, null, null, null, null);
}

//---retrieves a particular record---
public Cursor getRecord(long rowId) throws SQLException
{
    Cursor mCursor =
            db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
                            KEY_ITEM, KEY_LITRES},
                    KEY_ROWID + "=" + rowId, null, null, null, null, null);
    if (mCursor != null) {
        mCursor.moveToFirst();
    }
    return mCursor;
}

//---updates a record---
public boolean updateRecord(long rowId, String item, String litres)
{
    ContentValues args = new ContentValues();
    args.put(KEY_ITEM, item);
    args.put(KEY_LITRES, litres);
    //args.put(KEY_COURSE, course);
    //args.put(KEY_NOTES, notes);
    return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}

}

应用程序崩溃后的 logcat 错误是:(抱歉，我根本无法正确格式化格式)。

package com.pinchtapzoom;

Caused by: android.database.sqlite.SQLiteException: no such table: table1 (code 1): , while      compiling: SELECT id, item, litres FROM table1 
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)

Answer 1

您似乎想将表名称创建为分配并从table1访问数据。因此更改

private static final String DATABASE_TABLE = "table1";

至

private static final String DATABASE_TABLE = "assignments";