Java 如何将当前日期对应的数据从Sqlitedatabase读入setText

这是我的DatabaseCreator.java文件

package com.example.myapp;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DataBaseCreator extends SQLiteOpenHelper {
   private static String DB_PATH = "/data/data/com.example.myapp/databases/people.db";
   private static String DB_NAME = "people.db";
   private static int DB_VERSION = 1;
   public static String DATABASE_TABLE = "people_table";
   public String temp = "";

   private SQLiteDatabase myDataBase;
   private final Context myContext;

   public DataBaseCreator(Context context) {
       super(context, DB_NAME, null, DB_VERSION);
       this.myContext = context;

   }


   public void openDataBase(String date) throws SQLException {

       // Open the database
       String myPath = "/data/data/com.example.myapp/databases/people.db";
       myDataBase = SQLiteDatabase.openDatabase(myPath, null,
               SQLiteDatabase.OPEN_READONLY);
       passText(date);

   }

   public final String passText(String date) {

       Cursor cursor = myDataBase.query(DATABASE_TABLE, null, null, null,
               null, null, null);

       cursor.moveToFirst();

           temp += cursor.getString(1); 
       return temp;
   }

   @Override
   public void onCreate(SQLiteDatabase db) {
       // TODO Auto-generated method stub

   }

   @Override
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
       // TODO Auto-generated method stub

   }



}

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Calendar;


public class Activity6 extends AppCompatActivity {

    ArrayList<String > listItem;
    ArrayAdapter <String> adapter;

    ListView userList;




    DatabaseHelper db;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_6);

        TextView textView;
        TextView textview2;
        textView = findViewById(R.id.TextView2);
        textview2 = findViewById(R.id.textViewsecond);

        Calendar cal = Calendar.getInstance();

        int currentyear = cal.get(Calendar.YEAR);
        int currentmonth = cal.get(Calendar.MONTH);
        int currentday = cal.get(Calendar.DAY_OF_MONTH);

       String arr[]= {"January", "February","March", "April", "May", "June","July", "August","September","October","November","December"};

        String str1 = Integer.toString(currentday);
        String str2 = arr[currentmonth];
        String str3 = Integer.toString(currentyear);

        String str4 = str1 + " "+ str2 + " "+ str3;
        

        DataBaseCreator myDbHelper = new DataBaseCreator(this);

   

        myDbHelper.openDataBase(str4);

        textView.setText(String.valueOf(str4));

        textview2.setText(myDbHelper.temp);



        
    }






}

这是我的Activity6.java文件

package com.example.myapp;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DataBaseCreator extends SQLiteOpenHelper {
   private static String DB_PATH = "/data/data/com.example.myapp/databases/people.db";
   private static String DB_NAME = "people.db";
   private static int DB_VERSION = 1;
   public static String DATABASE_TABLE = "people_table";
   public String temp = "";

   private SQLiteDatabase myDataBase;
   private final Context myContext;

   public DataBaseCreator(Context context) {
       super(context, DB_NAME, null, DB_VERSION);
       this.myContext = context;

   }


   public void openDataBase(String date) throws SQLException {

       // Open the database
       String myPath = "/data/data/com.example.myapp/databases/people.db";
       myDataBase = SQLiteDatabase.openDatabase(myPath, null,
               SQLiteDatabase.OPEN_READONLY);
       passText(date);

   }

   public final String passText(String date) {

       Cursor cursor = myDataBase.query(DATABASE_TABLE, null, null, null,
               null, null, null);

       cursor.moveToFirst();

           temp += cursor.getString(1); 
       return temp;
   }

   @Override
   public void onCreate(SQLiteDatabase db) {
       // TODO Auto-generated method stub

   }

   @Override
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
       // TODO Auto-generated method stub

   }



}

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Calendar;


public class Activity6 extends AppCompatActivity {

    ArrayList<String > listItem;
    ArrayAdapter <String> adapter;

    ListView userList;




    DatabaseHelper db;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_6);

        TextView textView;
        TextView textview2;
        textView = findViewById(R.id.TextView2);
        textview2 = findViewById(R.id.textViewsecond);

        Calendar cal = Calendar.getInstance();

        int currentyear = cal.get(Calendar.YEAR);
        int currentmonth = cal.get(Calendar.MONTH);
        int currentday = cal.get(Calendar.DAY_OF_MONTH);

       String arr[]= {"January", "February","March", "April", "May", "June","July", "August","September","October","November","December"};

        String str1 = Integer.toString(currentday);
        String str2 = arr[currentmonth];
        String str3 = Integer.toString(currentyear);

        String str4 = str1 + " "+ str2 + " "+ str3;
        

        DataBaseCreator myDbHelper = new DataBaseCreator(this);

   

        myDbHelper.openDataBase(str4);

        textView.setText(String.valueOf(str4));

        textview2.setText(myDbHelper.temp);



        
    }






}

package com.example.myapp；
导入androidx.appcompat.app.appcompat活动；
导入android.content.Context；
导入android.database.Cursor；
导入android.database.SQLException；
导入android.database.sqlite.SQLiteDatabase；
导入android.database.sqlite.SQLiteException；
导入android.os.Bundle；
导入android.util.Log；
导入android.widget.ArrayAdapter；
导入android.widget.ListView；
导入android.widget.TextView；
导入java.io.FileOutputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.io.OutputStream；
导入java.util.ArrayList；
导入java.util.Calendar；
公共类活动6扩展了AppCompatActivity{
ArrayList列表项；
阵列适配器；
ListView用户列表；
数据库辅助数据库；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_6）；
文本视图文本视图；
文本视图文本视图2；
textView=findViewById（R.id.TextView2）；
textview2=findViewById（R.id.textViewsecond）；
Calendar cal=Calendar.getInstance（）；
int currentyear=cal.get（日历年）；
int currentmonth=cal.get（日历月）；
int currentday=cal.get（日历日/月）；
字符串arr[]={“一月”、“二月”、“三月”、“四月”、“五月”、“六月”、“七月”、“八月”、“九月”、“十月”、“十一月”、“十二月”}；
字符串str1=Integer.toString（currentday）；
字符串str2=arr[currentmount]；
字符串str3=Integer.toString（当前年份）；
字符串str4=str1+“”+str2+“”+str3；
DataBaseCreator myDbHelper=新的DataBaseCreator（此）；
openDataBase（str4）；
textView.setText（String.valueOf（str4））；
textview2.setText（myDbHelper.temp）；
}
}

我的数据库包含：

第1列-id，第2列-日期，第3列-任务

我需要的输出：

我作为str4传递的日期（也是数据库中第二列的值）必须用于从第三列获取任务（我正试图在passtext（）中执行此操作）

---

请帮助

为什么不使用“选择…从…从…何处…”编写正确的Sql查询？谢谢！当我给它：`int num=1；字符串数据=整数.toString（num）；SQLiteDatabase db=this.getWritableDatabase（）；Cursor cursor1=db.rawQuery（“从people_表中选择*，其中ID='data'，null）；返回游标1；=>游标1中没有返回任何内容，而当我给出ID=1时，将返回相应的行。请阅读文档，了解如何处理查询中的参数。