Ax8bnkNU

1package com.example.myapplication;
2
3import android.content.ContentValues;
4import android.content.Context;
5import android.database.Cursor;
6import android.database.SQLException;
7import android.database.sqlite.SQLiteDatabase;
8import android.database.sqlite.SQLiteOpenHelper;
9import android.util.Log;
10//https://www.journaldev.com/9438/android-sqlite-database-example-tutorial#opening-the-android-sqlite-database-file
11public class DBAdapter2 {
12    static final String KEY_ROWID = "_id";
13    static final String KEY_PLATE = "plate";
14    static final String KEY_OWNER = "owner";
15    static final String KEY_PAY = "pay";
16    static final String KEY_YEAR = "year";
17    static final String TAG = "DBAdapter";
18    static final String DATABASE_NAME = "MyDB";
19    static final String DATABASE_TABLE = "cars";
20    static final int DATABASE_VERSION = 1;
21    static final String DATABASE_CREATE =
22            "create table cars (_id integer primary key autoincrement, "
23                    + "plate text not null, owner text not null, pay text not null, year text not null);";
24    private Context context;
25    DatabaseHelper DBHelper;
26    SQLiteDatabase db;
27    public DBAdapter2(Context ctx)
28    {
29        this.context = ctx;
30        DBHelper = new DatabaseHelper(context);
31    }
32    private static class DatabaseHelper extends SQLiteOpenHelper
33    {
34        DatabaseHelper(Context context)
35        {
36            super(context, DATABASE_NAME, null, DATABASE_VERSION);
37        }
38        @Override
39        public void onCreate(SQLiteDatabase db)
40        {
41            try {
42                db.execSQL(DATABASE_CREATE);
43            } catch (SQLException e) {
44                e.printStackTrace();
45            }
46        }
47        @Override
48        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
49        {
50            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
51                    + newVersion + ", which will destroy all old data");
52            db.execSQL("DROP TABLE IF EXISTS cars");
53            onCreate(db);
54        }
55    }
56    //---opens the database---
57    public DBAdapter2 open() throws SQLException
58    {
59        db = DBHelper.getWritableDatabase();
60        return this;
61    }
62    //---closes the database---
63    public void close()
64    {
65        DBHelper.close();
66    }
67    //---insert a contact into the database---
68    public long insertContact(String plate, String owner, String pay,String year)
69    {
70        ContentValues initialValues = new ContentValues();
71        initialValues.put(KEY_PLATE, plate);
72        initialValues.put(KEY_OWNER, owner);
73        initialValues.put(KEY_PAY, pay);
74        initialValues.put(KEY_YEAR, year);
75        return db.insert(DATABASE_TABLE, null, initialValues);
76    }
77    //---deletes a particular contact---
78    public boolean deleteContact(long rowId)
79    {
80        return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
81    }
82    public boolean deleteall()
83    {
84        return db.delete(DATABASE_TABLE,null,null ) > 0;
85    }
86    //---retrieves all the contacts---
87    public Cursor getAllContacts()
88    {
89        return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_PLATE,
90                KEY_OWNER,KEY_PAY,KEY_YEAR}, null, null, null, null, null);
91    }
92    //---retrieves a particular contact---
93    public Cursor getContact(long rowId) throws SQLException
94    {
95        Cursor mCursor =
96                db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
97                                KEY_PLATE, KEY_OWNER,KEY_PAY,KEY_YEAR},
98                        KEY_ROWID + "=" + rowId, null,
99                        null, null, null, null);
100        if (mCursor != null) {
101            mCursor.moveToFirst();
102        }
103        return mCursor;
104    }
105    //---updates a contact---
106    public boolean updateContact(long rowId, String plate, String owner,String pay,String year)
107    {
108        ContentValues args = new ContentValues();
109        args.put(KEY_PLATE, plate);
110        args.put(KEY_OWNER, owner);
111        args.put(KEY_PAY, pay);
112        args.put(KEY_YEAR, year);
113        return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) >
114                0;
115    }
116}