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我想在数据库处理程序类中创建一个包含所有 RUD（减去 C）的多表数据库，但在帮助程序类中创建和更新所有表。

这是我一直用于单个表的内容：

package com.cc.folfapptest;

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

public class ConfigDatabaseHandler extends SQLiteOpenHelper {

    // All Static variables
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "AndroidSQLLiteDB";

    // Config table name
    private static final String TABLE_CONFIG = "Config";

    // Config Table Columns names
    private static final String KEY_ID = "id"; //
    private static final String KEY_VERSION = "Version";
    private static final String KEY_PRO_KEY = "ProKey";
    private static final String KEY_SERVERID = "ServerID";
    private static final String KEY_SERVERID_ALT = "ServerID_Alt";
    private static final String KEY_CURRENT_BAG_ID = "CurrentBagID";
    private static final String KEY_PLAYER_ID = "PlayerID"; 
    private static final String KEY_PLAYER_SERVER_ID = "PlayerServerID"; 

    String _currentBagID;
    String _playerID;
    String _playerServerID;

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

    // Creating Tables
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_CONFIG_TABLE = "CREATE TABLE " + TABLE_CONFIG + "("
                + KEY_ID + " INTEGER PRIMARY KEY," 
                + KEY_VERSION + " TEXT," 
                + KEY_PRO_KEY + " TEXT," 
                + KEY_SERVERID + " TEXT," 
                + KEY_SERVERID_ALT + " TEXT," 
                + KEY_CURRENT_BAG_ID + " TEXT," 
                + KEY_PLAYER_ID + " TEXT," 
                + KEY_PLAYER_SERVER_ID + " TEXT" 
                + ")";
        db.execSQL(CREATE_CONFIG_TABLE);
    }

    // Upgrading database
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONFIG);

        // Create tables again
        onCreate(db);
    }

    /**
     * All CRUD(Create, Read, Update, Delete) Operations
     */

    // Adding new config
    int addConfig(Config config) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_VERSION, config.getVersion()); // Version
        values.put(KEY_PRO_KEY, config.getProKey()); // ProKey
        values.put(KEY_SERVERID, config.getServerID()); 
        values.put(KEY_SERVERID_ALT, config.getServerID());
        values.put(KEY_CURRENT_BAG_ID, config.getCurrentBagID()); 
        values.put(KEY_PLAYER_ID, config.getPlayerID()); 
        values.put(KEY_PLAYER_SERVER_ID, config.getPlayerServerID());

        // Inserting Row
        long myReturnlong = db.insert(TABLE_CONFIG, null, values);
        int myReturnInt = (int)myReturnlong;
        //db.close(); // Closing database connection
        return myReturnInt;
    }

    // Getting Config
    Config getConfig(int id) {
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_CONFIG, new String[] { KEY_ID, KEY_VERSION, KEY_PRO_KEY, KEY_SERVERID, KEY_SERVERID_ALT, KEY_CURRENT_BAG_ID, KEY_PLAYER_ID, KEY_PLAYER_SERVER_ID}, KEY_ID + "=?",
                new String[] { String.valueOf(id) }, null, null, null, null);
        if (cursor != null)
            cursor.moveToFirst();

        Config config = new Config();
        config.setID(Integer.parseInt(cursor.getString(0)));
        config.setVersion(cursor.getString(1));
        config.setProKey(cursor.getString(2));
        config.setServerID(cursor.getString(3));
        config.setServerID_Alt(cursor.getString(4));
        config.setCurrentBagID(cursor.getString(5));
        config.setPlayerID(cursor.getString(6));
        config.setPlayerServerID(cursor.getString(7));
        // return player
        return config;
    }

    // Updating Config
    public int updateConfig(Config config) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_VERSION, config.getVersion()); // Version
        values.put(KEY_PRO_KEY, config.getProKey()); // ProKey
        values.put(KEY_SERVERID, config.getServerID()); // SERVERID
        values.put(KEY_SERVERID_ALT, config.getServerID_Alt()); // SERVERID
        values.put(KEY_CURRENT_BAG_ID, config.getCurrentBagID()); 
        values.put(KEY_PLAYER_ID, config.getPlayerID()); 
        values.put(KEY_PLAYER_SERVER_ID, config.getPlayerServerID());

        // updating row
        return db.update(TABLE_CONFIG, values, KEY_ID + " = ?",
                new String[] { String.valueOf(config.getID()) });
    }

    // Truncate Config Table
    public void truncateConfigTable() {
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_CONFIG, null, null);
    }
}

我正在查看代码以寻找解决此问题的方法，我想如果我只是不覆盖上述类功能中的 onCreate() onUpgrade() 并且只处理对表的所有创建和更改（不完全是，但喜欢）：

public class DataBaseHelper extends SQLiteOpenHelper {
public DataBaseHelper(Context context, String name,CursorFactory factory, int version) 
{
           super(context, name, factory, version);
}
// Called when no database exists in disk and the helper class needs
// to create a new one.
@Override
public void onCreate(SQLiteDatabase _db) 
{
        _db.execSQL(DatabaseFunc.DATABASE_CREATE);
        _db.execSQL(DatabaseFunc.DATABASE_CREATE2);

}
// Called when there is a database version mismatch meaning that the version
// of the database on disk needs to be upgraded to the current version.
@Override
public void onUpgrade(SQLiteDatabase _db, int _oldVersion, int _newVersion) 
{
        // Log the version upgrade.
        Log.w("TaskDBAdapter", "Upgrading from version " +_oldVersion + " to " +_newVersion + ", which will destroy all old data");

        // Upgrade the existing database to conform to the new version. Multiple
        // previous versions can be handled by comparing _oldVersion and _newVersion
        // values.
        // The simplest case is to drop the old table and create a new one.
        _db.execSQL("DROP TABLE IF EXISTS " + "LOGIN");
        _db.execSQL("DROP TABLE IF EXISTS " + "SMSREG");
        // Create a new one.
        onCreate(_db);
}

}

来自：android-sqllite-multiple-tables 会这样工作吗？我宁愿不必将 8 个表功能组合到一个文件中。这也将允许我快速转换它并开始将其用作多表设置。

我发现了很多单表 SQL Lite 示例，单表示例很糟糕，因为在“狂野”时，您会为单个表使用数据库吗？嘘。

4

1 回答 1

2

创建一个单例数据库类： 

public class Database extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "yourDatabaseName";

    //Declare a String for each Table name
    public static final String TABLE_NAME1 = "tableName1";
    public static final String TABLE_NAME2 = "tableName2";

    //Declare a SQL string for create each table
    private static final String CREATE_TABLE1 =
            "CREATE TABLE if not exists " + TABLE_NAME1 ..............";

    private static final String CREATE_TABLE2 =
            "CREATE TABLE if not exists " + TABLE_NAME2 .................";

    private static Database Singleton = null;
    private Context context;
    private static SQLiteDatabase Db;

    private Database(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

        this.context = context;
    }

    public static synchronized Database getInstance(Context c){
        if(Singleton == null) {
            Singleton = new Database(c.getApplicationContext());
            Db = Singleton.getWritableDatabase();
        }
        return Singleton;
    }

    public SQLiteDatabase getDatabase() {

        return Db;
    }

     public synchronized void close() {

         if (Singleton != null && Db.isOpen()) Db.close();
     }


    @Override
    protected void finalize() throws Throwable  {

        try{
            close();
        }
        finally{
            super.finalize();
        }

    @Override
    public void onCreate(SQLiteDatabase db) {

        //Create Tables
        db.execSQL(CREATE_TABLE1);
        db.execSQL(CREATE_TABLE2);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }
}

为表创建基类。这个类有处理表格的常用方法 

abstract class DatabaseTable {

    private SQLiteDatabase Db;
    private String TableName;

    public DatabaseTable(SQLiteDatabase db,String tableName) {

        this.TableName = tableName;
        this.Db = db;

    }

    public Cursor fetchAll() {

        Cursor cursor = Db.query(TableName, null, null, null, null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
        }
        return cursor;
    }

    public Cursor fetchAllOrderBy(String OrderField) {

        Cursor cursor = Db.query(TableName, null, null, null, null, null, OrderField);
        if (cursor != null) {
            cursor.moveToFirst();
        }
        return cursor;
    }

    public Cursor fetchById(long id) {

        Cursor cursor = Db.query(TableName, null, "_id = " + id, null, null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
        }
        return cursor;
    }

    public boolean deleteById(long id) {

        return Db.delete(TableName,"_id = " + id, null) > 0;
    }

    public boolean deleteAll() {

        return Db.delete(TableName,null, null) > 0;
    }

    public int getNumberRows() {

        return (int) DatabaseUtils.queryNumEntries(Db, TableName);
    }

}

现在您应该为要处理的每个表定义类： 

public class TbTable1 extends DatabaseTable{

    //Declare string for each field name
    public static final String FIELD_ID = "_id";
    public static final String FIELD_FIELDNAME1 = "fieldName1";
    public static final String FIELD_FIELDNAME2 = "fieldName2";
    ..........
    ..........

    private SQLiteDatabase Db;

    //Get the table name from Database class
    private static final String TableName = Database.TABLE_NAME1;


    public TbTable1(SQLiteDatabase db) {

        super(db,TableName);
        this.Db = db;
    }

    // Below define all the methods you need to access this table

    public long insertRecord(String value1, String value2) {

        ContentValues initialValues = new ContentValues();
        initialValues.put(FIELD_FIELDNAME2, value1);
        initialValues.put(FIELD_FIELDNAME2, value2);
        return Db.insert(TableName, null, initialValues);
    }

    ..............
    ..............
}

当你想对一张桌子做任何事情时： 

SQLiteDatabase Db = Database.getInstance(context).getDatabase();  
TbTable1 table1 = new TbTable1(Db);  
table1.insertRecord("Value1","Value2");
Cursor cursor = table1.fetchAll();

// do something with data

cursor.close();

希望这有帮助！

于 2013-10-28T21:18:09.127 回答