nGH9L0h6

1package com.example.admin.database;
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
11/**
12 * Created by admin on 19/4/2561.
13 */
14
15public class DBAdapter {
16    static final String KEY_ROWID = "_id";
17    static final String KEY_NAME = "name";
18    static final String KEY_EMAIL = "email";
19    static final String TAG = "DBAdapter";
20    static final String DATABASE_NAME = "MyDB";
21    static final String DATABASE_TABLE = "contacts";
22    static final int DATABASE_VERSION = 1;
23    static final String DATABASE_CREATE =
24            "create table contacts (_id integer primary key autoincrement, "
25            + "name text not null, email text not null);";
26    final Context context;
27    DatabaseHelper DBHelper;
28    SQLiteDatabase db;
29    public DBAdapter(Context ctx)
30    {
31        this.context = ctx;
32        DBHelper = new DatabaseHelper(context);
33    }
34
35    private static class DatabaseHelper extends SQLiteOpenHelper
36    {
37        DatabaseHelper(Context context)
38        {
39            super(context, DATABASE_NAME, null, DATABASE_VERSION);
40        }
41        @Override
42        public void onCreate(SQLiteDatabase db)
43        {
44            try {
45                db.execSQL(DATABASE_CREATE);
46            } catch (SQLException e) {
47                e.printStackTrace();
48            }
49        }
50        @Override
51        public void onUpgrade(SQLiteDatabase db, int oldVersion, int
52                newVersion)
53        {
54            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
55                            + newVersion + ", which will destroy all old data");
56            db.execSQL("DROP TABLE IF EXISTS contacts");
57            onCreate(db);
58        }
59    }
60    //---opens the database---
61    public DBAdapter open() throws SQLException{
62        db = DBHelper.getWritableDatabase();
63        return this;
64    }
65
66    //---closes the database---
67    public void close()
68    {
69        DBHelper.close();
70    }
71    //---insert a contact into the database---
72    public long insertContact(String name, String email)
73    {
74        ContentValues initialValues = new ContentValues();
75        initialValues.put(KEY_NAME, name);
76        initialValues.put(KEY_EMAIL, email);
77        return db.insert(DATABASE_TABLE, null, initialValues);
78    }
79    //---deletes a particular contact---
80    public boolean deleteContact(long rowId)
81    {
82        return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null)
83                > 0;
84    }
85    //---retrieves all the contacts---
86    public Cursor getAllContacts()
87    {
88        return db.query(DATABASE_TABLE, new String[] {KEY_ROWID,
89                KEY_NAME,
90                KEY_EMAIL}, null, null, null, null, null);
91    }
92
93    //---retrieves a particular contact---
94    public Cursor getContact(long rowId) throws SQLException
95    {
96        Cursor mCursor =
97                db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
98                                KEY_NAME, KEY_EMAIL},
99                        KEY_ROWID + "=" + rowId, null,
100                        null, null, null, null);
101        if (mCursor != null) {
102            mCursor.moveToFirst();
103        }
104        return mCursor;
105    }
106    //---updates a contact---
107    public boolean updateContact(long rowId, String name, String email)
108    {
109        ContentValues args = new ContentValues();
110        args.put(KEY_NAME, name);
111        args.put(KEY_EMAIL, email);
112        return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId,
113                null) >
114                0;
115    }
116    public boolean deleteAll(){
117        return db.delete(DATABASE_TABLE, "1", null) > 0;
118    }
119}