ib6S8H8S

1package com.example.lab2;
2import android.database.sqlite.SQLiteDatabase;
3import android.database.sqlite.SQLiteOpenHelper;
4import android.content.Context;
5import android.content.ContentValues;
6import android.database.Cursor;
7import android.util.Log;
8
9import java.util.ArrayList;
10import java.util.List;
11
12public class MyDBHandler extends SQLiteOpenHelper {
13    //information of database
14    private static final int DATABASE_VERSION = 2;
15    private static final String DATABASE_NAME = "studentDB.db";
16    public static final String TABLE_NAME = "Student";
17    public static final String COLUMN_ID = "StudentID";
18    public static final String COLUMN_NAME = "StudentName";
19    public static final String COLUMN_MARK = "StudentMark";
20
21    public MyDBHandler(Context context,
22        SQLiteDatabase.CursorFactory factory) {
23        super(context, DATABASE_NAME, factory, DATABASE_VERSION);
24    }
25    @Override
26    public void onCreate(SQLiteDatabase db) {
27        String CREATE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + "(" + COLUMN_ID +
28            "INTEGER" + COLUMN_NAME + " TEXT," + COLUMN_MARK + " INTEGER" + ")";
29        db.execSQL(CREATE_TABLE);
30    }
31
32    public String loadHandler() {
33        String result = "";
34        String query = "Select * FROM " + TABLE_NAME;
35        SQLiteDatabase db = this.getWritableDatabase();
36        Cursor cursor = db.rawQuery(query, null);
37        while (cursor.moveToNext()) {
38            int result_0 = cursor.getInt(0);
39            String result_1 = cursor.getString(1);
40            int result_2 = cursor.getInt(2);
41            result += String.valueOf(result_0) + " " + result_1 + result_2 + "" +
42                System.getProperty("line.separator");
43        }
44        cursor.close();
45        db.close();
46        return result;
47    }
48    public void addHandler(Student student) {
49        ContentValues values = new ContentValues();
50        values.put(COLUMN_ID, student.getID());
51        values.put(COLUMN_NAME, student.getStudentName());
52        values.put(COLUMN_MARK, student.getStudentMarks());
53        SQLiteDatabase db = this.getWritableDatabase();
54        db.insert(TABLE_NAME, null, values);
55        db.close();
56    }
57    public Student findHandler(int ID) {
58
59        String query = "Select * FROM " + TABLE_NAME + "WHERE" + COLUMN_NAME + " = " + "'" + ID + "'";
60        SQLiteDatabase db = this.getWritableDatabase();
61        Cursor cursor = db.rawQuery(query, null);
62        Student student = new Student();
63        if (cursor.moveToFirst()) {
64            cursor.moveToFirst();
65            student.setID(Integer.parseInt(cursor.getString(0)));
66            student.setStudentName(cursor.getString(1));
67            student.setStudentMarks(Integer.parseInt(cursor.getString(2)));
68            cursor.close();
69        } else {
70            student = null;
71        }
72        db.close();
73        return student;
74    }
75    public boolean deleteHandler(int ID) {
76
77        boolean result = false;
78        String query = "Select*FROM" + TABLE_NAME + "WHERE" + COLUMN_ID + "= '" + String.valueOf(ID) + "'";
79        SQLiteDatabase db = this.getWritableDatabase();
80        Cursor cursor = db.rawQuery(query, null);
81        Student student = new Student();
82        if (cursor.moveToFirst()) {
83            student.setID(Integer.parseInt(cursor.getString(0)));
84            db.delete(TABLE_NAME, COLUMN_ID + "=?",
85                new String[] {
86                    String.valueOf(student.getID())
87                });
88            cursor.close();
89            result = true;
90        }
91        db.close();
92        return result;
93    }
94
95
96    public boolean updateHandler(int ID, String name, String marks) {
97        SQLiteDatabase db = this.getWritableDatabase();
98        ContentValues args = new ContentValues();
99        args.put(COLUMN_ID, ID);
100        args.put(COLUMN_NAME, name);
101        args.put(COLUMN_MARK, marks);
102        return db.update(TABLE_NAME, args, COLUMN_ID + "=" + ID, null) > 0;
103    }
104    public void onUpgrade(SQLiteDatabase db, int i, int i1) {}
105    public ArrayList < Student > findAll() {
106        SQLiteDatabase db = this.getReadableDatabase();
107        Cursor cursor = db.rawQuery("select * from " + TABLE_NAME, null);
108
109        ArrayList < Student > fileName = new ArrayList < > ();
110
111        if (cursor.moveToFirst()) {
112            String name = cursor.getString(cursor.getColumnIndex(COLUMN_NAME));
113            String marks = cursor.getString(cursor.getColumnIndex(COLUMN_MARK));
114            String id = cursor.getString(cursor.getColumnIndex(COLUMN_ID));
115            Student s = new Student(Integer.parseInt(id), name, Integer.parseInt(marks));
116            fileName.add(s);
117            while (cursor.moveToNext()) {
118                name = cursor.getString(cursor.getColumnIndex(COLUMN_NAME));
119                marks = cursor.getString(cursor.getColumnIndex(COLUMN_MARK));
120                id = cursor.getString(cursor.getColumnIndex(COLUMN_ID));
121                s = new Student(Integer.parseInt(id), name, Integer.parseInt(marks));
122            }
123        }
124        cursor.close();
125        db.close();
126        return fileName;
127    }
128}