// declare table Category
@DbTable(tableName = "category")
public class Category {
    @DbColumn
    @DbPrimaryKey(autoincrement = false)
    public int sid;

    @DbColumn
    public String name;
}

// declare table Item
@DbTable(tableName = "item")
public class Item {
    @DbColumn
    @DbPrimaryKey
    public int _id;

    @DbColumn
    public String name;

    @DbColumn(varcharLength = 1000)
    public String content;

    @DbColumn(notNull = true)
    public String text;

    @DbColumn
    public boolean isFav;

    @DbColumn
    public boolean isUseful;

    @DbColumn
    public String shareTitle;

    @DbColumn(name = "p1")
    public float percent;

    @DbColumn(name = "p2")
    public double percentD;

    @Override
    public String toString() {
        return "id:" + _id + ",name:" + name
                + ",content:" + content + ",text:" + text
                + ",isFav:" + isFav + ",isUseful:"
                + isUseful + ",shareTitle:" + shareTitle
                + ",percent:" + percent + ",percentD:" + percentD;
    }
}

// declare database
public class DbStore {
    public static final String DB_NAME = "item.db";
    public static final int DB_VERSION = 3;

    static final DbTableDefinition ITEM_TABLE = DbTableGenerator.generate(Item.class);
    static final DbTableDefinition CATEGORY_TABLE = DbTableGenerator.generate(Category.class);

    // declare upgrade db sql
    static DbUpgradeDefinition DB_1_2 = new DbUpgradeDefinition.Builder().fromVersion(1).toVersion(2)
            .sql(new String[]{
                    "ALTER TABLE 'item' add 'shareTitle' VARCHAR(300)",
                    "ALTER TABLE 'item' add 'shareContent' VARCHAR(700)"
            }).build();

    static DbUpgradeDefinition DB_2_3 = new DbUpgradeDefinition.Builder().fromVersion(2).toVersion(3)
            .sql(new String[]{
                    CATEGORY_TABLE.creationSql()
            }).build();

    static final DbDefinition ITEM_DB =
            new DbDefinition.Builder().version(DB_VERSION).name(DB_NAME)
                    .table(ITEM_TABLE)
                    .table(CATEGORY_TABLE)
                    .upgrade(DB_1_2)
                    .upgrade(DB_2_3)
                    .build();
}

// declare a DbHelper
public class DbHelper {
    private static DbHelper sInstance = null;
    @NonNull
    public final DbTemplateTableModel<Item> itemDbTemplateTableModel;
    @NonNull
    public final DbTemplateTableModel<Category> categoryDbTemplateTableModel;

    private DbHelper(Context context) {
        DbDataBase stickerDb = new DbDataBase(context.getApplicationContext(), DbStore.ITEM_DB);
        try {
            stickerDb.init();
        } catch (Exception e) {
            //ignore
        }
        itemDbTemplateTableModel = new DbTemplateTableModel<>(DbStore.ITEM_TABLE,
                stickerDb, Item.class);
        categoryDbTemplateTableModel = new DbTemplateTableModel<>(DbStore.CATEGORY_TABLE,
                stickerDb, Category.class);
    }

    public static DbHelper getInstance(Context context) {
        if (sInstance == null) {
            synchronized (DbHelper.class) {
                if (sInstance == null) {
                    sInstance = new DbHelper(context);
                }
            }
        }
        return sInstance;
    }
}

// to use
Item item1 = new Item();
item1.name = "hahha1";
item1.content = "content1";
item1.text = "text1";
item1.isFav = true;
item1.percent = 0.3f;
item1.percentD = 2.7d;

// insert
DbHelper.getInstance(this).itemDbTemplateTableModel.insert(item1);

TextView textView = (TextView) findViewById(R.id.text);
// get all
for (Item item : DbHelper.getInstance(this).itemDbTemplateTableModel.getAll()) {
  textView.setText(item.toString());
}