android stuio中的MySQLiteOpenHelper创建三个表

好的，下面是一个示例代码，用于在 Android Studio 中创建三个表：

public class MyDatabaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "mydatabase.db";
    private static final int DATABASE_VERSION = 1;

    // Table 1
    private static final String TABLE_1_NAME = "table1";
    private static final String TABLE_1_COLUMN_1 = "id";
    private static final String TABLE_1_COLUMN_2 = "name";
    private static final String TABLE_1_COLUMN_3 = "age";
    private static final String TABLE_1_CREATE =
            "CREATE TABLE " + TABLE_1_NAME + " (" +
                    TABLE_1_COLUMN_1 + " INTEGER PRIMARY KEY, " +
                    TABLE_1_COLUMN_2 + " TEXT, " +
                    TABLE_1_COLUMN_3 + " INTEGER)";

    // Table 2
    private static final String TABLE_2_NAME = "table2";
    private static final String TABLE_2_COLUMN_1 = "id";
    private static final String TABLE_2_COLUMN_2 = "address";
    private static final String TABLE_2_COLUMN_3 = "phone";
    private static final String TABLE_2_CREATE =
            "CREATE TABLE " + TABLE_2_NAME + " (" +
                    TABLE_2_COLUMN_1 + " INTEGER PRIMARY KEY, " +
                    TABLE_2_COLUMN_2 + " TEXT, " +
                    TABLE_2_COLUMN_3 + " TEXT)";

    // Table 3
    private static final String TABLE_3_NAME = "table3";
    private static final String TABLE_3_COLUMN_1 = "id";
    private static final String TABLE_3_COLUMN_2 = "email";
    private static final String TABLE_3_COLUMN_3 = "password";
    private static final String TABLE_3_CREATE =
            "CREATE TABLE " + TABLE_3_NAME + " (" +
                    TABLE_3_COLUMN_1 + " INTEGER PRIMARY KEY, " +
                    TABLE_3_COLUMN_2 + " TEXT, " +
                    TABLE_3_COLUMN_3 + " TEXT)";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(TABLE_1_CREATE);
        db.execSQL(TABLE_2_CREATE);
        db.execSQL(TABLE_3_CREATE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // 如果需要升级数据库，可以在这里处理
    }
}

在这个示例代码中，我们创建了三个表：`table1`、`table2` 和 `table3`。每个表都有不同的列，可以根据自己的需求进行修改。在 `onCreate` 方法中，我们执行了三个 SQL 语句，用于创建这三个表。在实际使用时，可以根据需要进行修改。