EQCsxDsF

1
2
3https://www.journaldev.com/9438/android-sqlite-database-example-tutorial
4
5=======dbhelper=======
6import android.content.Context;
7import android.database.sqlite.SQLiteDatabase;
8import android.database.sqlite.SQLiteOpenHelper;
9
10public class DatabaseHelper extends SQLiteOpenHelper {
11
12    // Table Name
13    public static final String TABLE_NAME = "COUNTRIES";
14
15    // Table columns
16    public static final String _ID = "_id";
17    public static final String SUBJECT = "subject";
18    public static final String DESC = "description";
19
20    // Database Information
21    static final String DB_NAME = "JOURNALDEV_COUNTRIES.DB";
22
23    // database version
24    static final int DB_VERSION = 1;
25
26    // Creating table query
27    private static final String CREATE_TABLE = "create table " + TABLE_NAME + "(" + _ID
28            + " INTEGER PRIMARY KEY AUTOINCREMENT, " + SUBJECT + " TEXT NOT NULL, " + DESC + " TEXT);";
29
30    public DatabaseHelper(Context context) {
31        super(context, DB_NAME, null, DB_VERSION);
32    }
33
34    @Override
35    public void onCreate(SQLiteDatabase db) {
36        db.execSQL(CREATE_TABLE);
37    }
38
39    @Override
40    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
41        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
42        onCreate(db);
43    }
44}
45=======dbhelper  close=======
46
47
48=======db maneger=======
49
50public class DBManager {
51
52    private DatabaseHelper dbHelper;
53
54    private Context context;
55
56    private SQLiteDatabase database;
57
58    public DBManager(Context c) {
59        context = c;
60    }
61
62    public DBManager open() throws SQLException {
63        dbHelper = new DatabaseHelper(context);
64        database = dbHelper.getWritableDatabase();
65        return this;
66    }
67
68    public void close() {
69        dbHelper.close();
70    }
71
72    public void insert(String name, String desc) {
73        ContentValues contentValue = new ContentValues();
74        contentValue.put(DatabaseHelper.SUBJECT, name);
75        contentValue.put(DatabaseHelper.DESC, desc);
76        database.insert(DatabaseHelper.TABLE_NAME, null, contentValue);
77    }
78
79    public Cursor fetch() {
80        String[] columns = new String[] { DatabaseHelper._ID, DatabaseHelper.SUBJECT, DatabaseHelper.DESC };
81        Cursor cursor = database.query(DatabaseHelper.TABLE_NAME, columns, null, null, null, null, null);
82        if (cursor != null) {
83            cursor.moveToFirst();
84        }
85        return cursor;
86    }
87
88    public int update(long _id, String name, String desc) {
89        ContentValues contentValues = new ContentValues();
90        contentValues.put(DatabaseHelper.SUBJECT, name);
91        contentValues.put(DatabaseHelper.DESC, desc);
92        int i = database.update(DatabaseHelper.TABLE_NAME, contentValues, DatabaseHelper._ID + " = " + _id, null);
93        return i;
94    }
95
96    public void delete(long _id) {
97        database.delete(DatabaseHelper.TABLE_NAME, DatabaseHelper._ID + "=" + _id, null);
98    }
99
100}
101=======db maneger  Close=======