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好的，所以，我想创建一个数据库来存储三个表，并在每次应用程序启动时存储数据（表、列和属性值）。我不需要添加 GUI 来添加或删除元组，但是在每次创建时对其进行硬编码是可以的（这是一个学生项目）。我尝试按照“4.教程：使用 SQLite”这个页面，这很棒，除了它确实添加了 GUI，并且只为单个表制作。

正如教程作者在文档前面提到的那样，我为每个表创建了一个类，并且我设置了 MySQLiteHelper 类，如下所示：

...
public class BFAppOpenHelper extends SQLiteOpenHelper {

// The 'crags'-table name and columns
public static final String CRAGS_TABLE = "crags";
public static final String CRAG_NAME = "cname";
public static final String CRAG_MINGRADE = "minGrade";
public static final String CRAG_MAXGRADE = "maxGrade";
public static final String CRAG_STEEP = "steep";
public static final String CRAG_AREA = "area";
public static final String CRAG_DESCRIPTION = "description";
public static final String CRAG_APPROACH = "appr_time";

// The 'routes'-table name and columns
public static final String ROUTES_TABLE = "routes";
public static final String ROUTE_NAME = "rname";
public static final String ROUTE_GRADE = "grade";
public static final String ROUTE_HEIGHT = "height";
public static final String ROUTE_STARS = "stars";
public static final String ROUTE_BOLTS = "bolts";
public static final String ROUTE_FIRST = "first";
public static final String ROUTE_NO = "number";
public static final String ROUTE_REBOLTED = "rebolted";

// The 'crag_images'-table name and columns
public static final String CRAG_IMAGES_TABLE = "crag_images";
public static final String CRAG_IMAGE_CRAG_NAME = "cname";
public static final String CRAG_IMAGE_IMAGE = "image";

// Database information
private static final String DATABASE_NAME = "BFApp.db";
private static final int DATABASE_VERSION = 1;

// The SQL-script for creating the 'crags'-table
private static final String CRAGS_TABLE_CREATE = "CREATE TABLE " + 
    CRAGS_TABLE + " (" 
        + CRAG_NAME + " TEXT NOT NULL, "
        + CRAG_MINGRADE + " TEXT NOT NULL,"
        + CRAG_MAXGRADE + " TEXT NOT NULL,"
        + CRAG_STEEP + " NUMBER NOT NULL,"
        + CRAG_AREA + " TEXT NOT NULL,"
        + CRAG_DESCRIPTION + " TEXT,"
        + CRAG_APPROACH + " NUMBER,"
        + " PRIMARY KEY (" + CRAG_NAME + "));";

// The SQL-script for creating the 'routes'-table
private static final String ROUTES_TABLE_CREATE = "CREATE TABLE " + 
    ROUTES_TABLE + " (" 
        + ROUTE_NAME + " TEXT NOT NULL, "
        + ROUTE_GRADE + " TEXT NOT NULL,"
        + ROUTE_HEIGHT + " NUMBER NOT NULL,"
        + ROUTE_STARS + " NUMBER NOT NULL,"
        + ROUTE_BOLTS + " NUMBER NOT NULL,"
        + ROUTE_FIRST + " TEXT,"
        + ROUTE_NO + " NUMBER,"
        + ROUTE_REBOLTED + "TEXT,"
        + " PRIMARY KEY (" + ROUTE_NAME + "));";

// The SQL-script for creating the 'crag_images'-table
private static final String CRAG_IMAGES_TABLE_CREATE = "CREATE TABLE " + 
    ROUTES_TABLE + " (" 
        + CRAG_IMAGE_CRAG_NAME + " TEXT PRIMARY KEY, "
        + CRAG_IMAGE_IMAGE + "TEXT,"
        + " FOREIGN KEY(" + CRAG_IMAGE_CRAG_NAME + ") REFERENCES " + CRAGS_TABLE + "(" + CRAG_NAME + "),"
        + " PRIMARY KEY(" + CRAG_IMAGE_CRAG_NAME + ", " + CRAG_IMAGE_IMAGE + "));";

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

@Override
public void onCreate(SQLiteDatabase database) {
    database.execSQL(CRAGS_TABLE_CREATE);
    database.execSQL(ROUTES_TABLE_CREATE);
    database.execSQL(CRAG_IMAGES_TABLE_CREATE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.w(BFAppOpenHelper.class.getName(),
        "Upgrading database from version " + oldVersion + " to "
        + newVersion + ", which will destroy all old data");
    db.execSQL("DROP TABLE IF EXISTS " + CRAGS_TABLE);
    onCreate(db);
}

现在，我已经明白我需要创建一个 DataSource 类，如教程中所述，但是我需要为每个表创建一个，还是需要使它适用于所有表，如果是，如何?

第一个stackoverflow问题，请让我知道它是否应该改写，或者它是否过于具体或不够具体。

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