如何在 Android Studio 中正确使用 database.raw 查询?

如何解决如何在 Android Studio 中正确使用 database.raw 查询?

我一直在尝试制作一个锻炼应用程序,它将解析我创建的数据库并从我的数据表中提取特定值。我的表格包含经验值(初学者或经验丰富的)、设备(负重或无负重)和锻炼(例如:俯卧撑)。我想根据用户是否是初学者并想要重量或我可以使用这些参数的任何其他条件来获取锻炼。我制作了一个数据库助手并有使用 database.raw 查询的代码,但是每次我尝试通过从练习数据表(我的数据表的名称)中选择设备和经验来进行查询时,它都会给我同样的错误。下面是eh数据库助手的代码和我引用的具体方法(getAllData)。错误也显示为好。任何帮助都会很棒,谢谢


    public static final String TABLE_EXERCISES = "exercises";
    public static final String COLUMN_ID = "_id";
    public static final String COLUMN_EXPERIENCE = "experience";
    public static final String COLUMN_EQUIPMENT = "equipment";
    public static final String COLUMN_WORKOUT = "workout";
    public static final String DATABASE_NAME = "exercises.db";
    private static final int DATABASE_VERSION = 1;

    // Database creation sql statement


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

    @Override
    public void onCreate(SQLiteDatabase database) {
        database.execSQL("create table " + TABLE_EXERCISES +" (_id INTEGER PRIMARY KEY AUTOINCREMENT,experience TEXT,equipment TEXT,workout TEXT)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) {
        Log.w(MySQLiteHelper.class.getName(),"Upgrading database from version " + oldVersion + " to "
                        + newVersion + ",which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_EXERCISES);
        onCreate(db);
    }
    public boolean insertData(String experience,String equipment,String workout){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COLUMN_EXPERIENCE,experience);
        contentValues.put(COLUMN_EQUIPMENT,equipment);
        contentValues.put(COLUMN_WORKOUT,workout);
        long result = db.insert(TABLE_EXERCISES,contentValues);
        if(result == -1)
            return false;
        else
            return true;
    }
    public Cursor getAllData(){
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery("SELECT equipment,experience FROM exercises WHERE experience = ? AND equipment = ?",new String[] {"beginner","weights"});
        //Cursor res = db.rawQuery("select * from "  + TABLE_EXERCISES,null);
        if (res.moveToFirst()) {
            return res;
        }
       return null;
    }
}


----------
Error:

E/CursorWindow: Failed to read row 1,column 2 from a CursorWindow which has 140 rows,2 columns.
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.hfad.workoutmaker,PID: 32245
    java.lang.IllegalStateException: Couldn't read row 1,col 2 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.
        at android.database.CursorWindow.nativeGetString(Native Method)

版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。

相关推荐


使用本地python环境可以成功执行 import pandas as pd import matplotlib.pyplot as plt # 设置字体 plt.rcParams['font.sans-serif'] = ['SimHei'] # 能正确显示负号 p
错误1:Request method ‘DELETE‘ not supported 错误还原:controller层有一个接口,访问该接口时报错:Request method ‘DELETE‘ not supported 错误原因:没有接收到前端传入的参数,修改为如下 参考 错误2:cannot r
错误1:启动docker镜像时报错:Error response from daemon: driver failed programming external connectivity on endpoint quirky_allen 解决方法:重启docker -> systemctl r
错误1:private field ‘xxx‘ is never assigned 按Altʾnter快捷键,选择第2项 参考:https://blog.csdn.net/shi_hong_fei_hei/article/details/88814070 错误2:启动时报错,不能找到主启动类 #
报错如下,通过源不能下载,最后警告pip需升级版本 Requirement already satisfied: pip in c:\users\ychen\appdata\local\programs\python\python310\lib\site-packages (22.0.4) Coll
错误1:maven打包报错 错误还原:使用maven打包项目时报错如下 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources)
错误1:服务调用时报错 服务消费者模块assess通过openFeign调用服务提供者模块hires 如下为服务提供者模块hires的控制层接口 @RestController @RequestMapping("/hires") public class FeignControl
错误1:运行项目后报如下错误 解决方案 报错2:Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project sb 解决方案:在pom.
参考 错误原因 过滤器或拦截器在生效时,redisTemplate还没有注入 解决方案:在注入容器时就生效 @Component //项目运行时就注入Spring容器 public class RedisBean { @Resource private RedisTemplate<String
使用vite构建项目报错 C:\Users\ychen\work>npm init @vitejs/app @vitejs/create-app is deprecated, use npm init vite instead C:\Users\ychen\AppData\Local\npm-
参考1 参考2 解决方案 # 点击安装源 协议选择 http:// 路径填写 mirrors.aliyun.com/centos/8.3.2011/BaseOS/x86_64/os URL类型 软件库URL 其他路径 # 版本 7 mirrors.aliyun.com/centos/7/os/x86
报错1 [root@slave1 data_mocker]# kafka-console-consumer.sh --bootstrap-server slave1:9092 --topic topic_db [2023-12-19 18:31:12,770] WARN [Consumer clie
错误1 # 重写数据 hive (edu)> insert overwrite table dwd_trade_cart_add_inc > select data.id, > data.user_id, > data.course_id, > date_format(
错误1 hive (edu)> insert into huanhuan values(1,'haoge'); Query ID = root_20240110071417_fe1517ad-3607-41f4-bdcf-d00b98ac443e Total jobs = 1
报错1:执行到如下就不执行了,没有显示Successfully registered new MBean. [root@slave1 bin]# /usr/local/software/flume-1.9.0/bin/flume-ng agent -n a1 -c /usr/local/softwa
虚拟及没有启动任何服务器查看jps会显示jps,如果没有显示任何东西 [root@slave2 ~]# jps 9647 Jps 解决方案 # 进入/tmp查看 [root@slave1 dfs]# cd /tmp [root@slave1 tmp]# ll 总用量 48 drwxr-xr-x. 2
报错1 hive> show databases; OK Failed with exception java.io.IOException:java.lang.RuntimeException: Error in configuring object Time taken: 0.474 se
报错1 [root@localhost ~]# vim -bash: vim: 未找到命令 安装vim yum -y install vim* # 查看是否安装成功 [root@hadoop01 hadoop]# rpm -qa |grep vim vim-X11-7.4.629-8.el7_9.x
修改hadoop配置 vi /usr/local/software/hadoop-2.9.2/etc/hadoop/yarn-site.xml # 添加如下 <configuration> <property> <name>yarn.nodemanager.res