如何在android sqlite中设置限制和条件

Question

我有一个名为DB Helper的类。在这个类中，我传递了2个字符串，其中包含当前日期和偏移的名称，但我不知道为什么它无法打开数据库并从中读取。我认为这是因为两个查询中有限制和当前日期。 任何人都可以指导我解决它吗？ 感谢

这是我的代码：

package com.hasti.kamali.amoozeshzaban;

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

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.SQLException;
import java.util.ArrayList;

public class DataBaseHelper extends SQLiteOpenHelper {

private static String DB_PATH = "/data/data/com.hasti.kamali.amoozeshzaban/databases/";

private String TABLE_NAME = "Words";
private String TABLE_TRANSLATE = "meaningp";
private String TABLE_LESSION = "lesson";
private String KEY_NAME = "word";
private String TABLE_DAY = "day";
private String KEY_ID = "id";
private String TABLE_PREADD = "pron";
ArrayList<WordEntity> list = new ArrayList<>();

String[] allCulomns = {KEY_ID, KEY_NAME, TABLE_TRANSLATE, TABLE_LESSION, TABLE_DAY, TABLE_PREADD};
private static String DB_NAME = "words.sqlite";
public static SQLiteDatabase myDataBase;
private final Context myContext;

public DataBaseHelper(Context context) {
    super(context, DB_NAME, null, 5);
    this.myContext = context;
}

public void createDataBase() throws IOException {

    boolean dbExist = checkDataBase();

    if (dbExist) {            

    } else {

        this.getReadableDatabase();

        try {
            copyDataBase();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

private boolean checkDataBase() {

    SQLiteDatabase checkDB = null;

    try {
        String myPath = DB_PATH + DB_NAME;

        checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.CREATE_IF_NECESSARY);

    } catch (SQLiteException e) {
    }

    if (checkDB != null) {
        checkDB.close();
    }

    return checkDB != null ? true : false;
}

private void copyDataBase() throws IOException {

    InputStream myInput = myContext.getAssets().open(DB_NAME);
    String outFileName = DB_PATH + DB_NAME;

    OutputStream myOutput = new FileOutputStream(outFileName);
    byte[] buffer = new byte[1024];

    int length;

    while ((length = myInput.read(buffer)) > 0) {
        myOutput.write(buffer, 0, length);
    }

    myOutput.flush();
    myOutput.close();
    myInput.close();
}

public void openDataBase() throws SQLException, IOException {

    try {

    } catch (SQLiteException e) {
        e.printStackTrace();
    }

    String myPath = DB_PATH + DB_NAME;

    File file = new File(myPath);
    if (file.exists() && !file.isDirectory())
        this.myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);

    else
        createDataBase();
}

public void update(WordEntity word) {

    ContentValues values = new ContentValues();
    values.put(TABLE_PREADD, word.getPreadd());
    values.put(TABLE_DAY, word.getDate());
    this.myDataBase.update(TABLE_NAME, values, KEY_ID + " =" + word.getId(), null);
}

@Override

public synchronized void close() {

    if (myDataBase != null)
        myDataBase.close();
        super.close();
}

public Cursor query(String table, String[] columns, String selection,
                    String[] selectionArgs, String groupBy, String having,
                    String orderBy) {
    return myDataBase.query("database", null, null, null, null, null, null);
}

@Override
public void onCreate(SQLiteDatabase db) {
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    if (newVersion > oldVersion)
        try {
            Log.e("db", "upgrade");
            copyDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }
}

public ArrayList<WordEntity> getAllTodaysWords(String currentdate,String offset) {
    try {
        Cursor cursor = myDataBase.query(TABLE_NAME, allCulomns, TABLE_LESSION+"=1", null, null, null, null, "2,"+offset+"");

        while (cursor.moveToNext()) {
            int id = cursor.getInt(cursor.getColumnIndex(KEY_ID));
            String title = cursor.getString(cursor.getColumnIndex(KEY_NAME));
            int session = cursor.getInt(cursor.getColumnIndex(TABLE_LESSION));
            String date = cursor.getColumnName(cursor.getColumnIndex(TABLE_DAY));
            String meaning = cursor.getString(cursor.getColumnIndex(TABLE_TRANSLATE));
            String preadd = cursor.getString(cursor.getColumnIndex(TABLE_PREADD));
            Log.e("sami", title);

            list.add(new WordEntity(id, title, meaning, date, session, preadd));
        }

        try {

            Cursor cursor1 = myDataBase.query(TABLE_NAME, allCulomns, TABLE_DAY + "=" + currentdate, null, null, null,null);

            while (cursor1.moveToNext()) {
                int id1 = cursor1.getInt(cursor1.getColumnIndex(KEY_ID));
                String title1 = cursor1.getString(cursor1.getColumnIndex(KEY_NAME));
                int session1 = cursor1.getInt(cursor1.getColumnIndex(TABLE_LESSION));
                String date1 = cursor1.getColumnName(cursor1.getColumnIndex(TABLE_DAY));
                String meaning1 = cursor1.getString(cursor1.getColumnIndex(TABLE_TRANSLATE));
                String preadd1 = cursor1.getString(cursor1.getColumnIndex(TABLE_PREADD));

                list.add(new WordEntity(id1, title1, meaning1, date1, session1, preadd1));
            }
        } catch (Exception e) {
        }
    } catch (Exception e) {
    }
    return list;
}
}