app/src/main/java/com/example/database/DataBaseHelper.java - master - TON618OFF/Android-Studio-Using-Database

app/src/main/java/com/example/database/DataBaseHelper.java
75 строк3 KB
TON618OFF
release
21 ноя 2024, 20:43
21 ноя 2024, 20:435b843b5
package com.example.database;

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

import androidx.annotation.Nullable;

public class DataBaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "book_db";
    private static final int SCHEMA = 1;
    static final String TABLE_NAME = "books";
    public static final String COLUMN_ID = "id_book";

    public static final String COLUMN_NAME = "book_name";
    public static final String COLUMN_AUTHOR = "book_author";

    public DataBaseHelper(@Nullable Context context) {
        super(context, DATABASE_NAME, null, SCHEMA);
    }

    public DataBaseHelper(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL("CREATE TABLE " + TABLE_NAME + " ("
                + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + COLUMN_NAME + " TEXT, "
                + COLUMN_AUTHOR + " TEXT);");
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
        sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(sqLiteDatabase);
    }

    public long addBook(String bookName, String bookAuthor) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, bookName);
        values.put(COLUMN_AUTHOR, bookAuthor);

        long result = db.insert(TABLE_NAME, null, values);
        db.close();
        return result;
    }

    public Cursor getAllBooks() {
        SQLiteDatabase db = this.getReadableDatabase();
        return  db.query(TABLE_NAME, null, null, null, null, null, null);
    }

    public int deleteBookById(long bookId) {
        SQLiteDatabase db = this.getWritableDatabase();
        int result = db.delete(TABLE_NAME, COLUMN_ID + " = ?", new String[]{String.valueOf(bookId)});
        db.close();
        return result;
    }

    public int updateBook(int bookId, String newName, String newAuthor) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, newName);
        values.put(COLUMN_AUTHOR, newAuthor);

        int result = db.update(TABLE_NAME, values, COLUMN_ID + " = ?", new String[]{String.valueOf(bookId)});
        db.close();
        return result;
    }
}