package cn.lblbc.notepad.db; import ohos.app.Context;#改一改 import ohos.data.DatabaseHelper; import ohos.data.orm.OrmContext; import ohos.data.orm.OrmPredicates; import java.util.List; /** * 厦门大学计算机专业 | 前华为工程师 * 专注《零基础学编程系列》 http://lblbc.cn/blog * 包含:Java | 安卓 | 前端 | Flutter | iOS | 小程序 | 鸿蒙 * 公众号:蓝不蓝编程 */ public class DbHelper { private static DbHelper dbHelper = new DbHelper(); private OrmContext ormContext; private DbHelper() { } public static DbHelper getInstance() { return dbHelper; } public void initDb(Context context) { DatabaseHelper databaseHelper = new DatabaseHelper(context); ormContext = databaseHelper.getOrmContext("lblDb", "lblDb.db", NoteDatabase.class); } public void add(String content) { Note note = new Note(); note.setId(System.currentTimeMillis()); note.setContent(content); ormContext.insert(note); ormContext.flush(); } public List query() { OrmPredicates ormPredicates = ormContext.where(Note.class); return ormContext.query(ormPredicates); } public Note query(long noteId) { OrmPredicates ormPredicates = ormContext.where(Note.class).equalTo("id", noteId + ""); List noteList = ormContext.query(ormPredicates); Note note = null; if (!noteList.isEmpty()) { note = noteList.get(0); } return note; } public void update(Note note) { ormContext.update(note); ormContext.flush(); } public void delete(long noteId) { OrmPredicates ormPredicates = ormContext.where(Note.class).equalTo("id", noteId + ""); ormContext.delete(ormPredicates); ormContext.flush(); } }