cHspY1yK

1SQLiteDatabase db = this.getReadableDatabase();
2	
3public StudentsinLib getId(int id){
4
5    String selectQuery = "SELECT * FROM " + STUDENTDATABASETABLE_NAME + " WHERE "+ COL + " ="+id;
6
7    SQLiteDatabase db = this.getReadableDatabase(); // ======> THE EMULATOR POINTS HERE
8    Cursor cursor = db.rawQuery(selectQuery, null);
9
10    if (cursor != null)
11        cursor.moveToFirst();
12
13    StudentsinLib studentsinLib = new StudentsinLib();
14    studentsinLib.setId(cursor.getInt(0));
15    studentsinLib.setName(cursor.getString(1));
16    studentsinLib.setNumber(cursor.getString(2));
17
18    //log
19    Log.d("getStudent(" + id + ")", StudentsinLib.toString());
20    // 5. return student
21    return studentsinLib;
22}
23	
24public class StudentsinLibDatabase extends SQLiteOpenHelper {
25// Database Version
26private static final int DATABASE_VERSION = 1;
27// Database Name
28private static final String STUDENTDATABASE_NAME = "StudentsinLibDB";
29// Table Content
30private static final String STUDENTDATABASETABLE_NAME = "StudentsinLibTB";
31private static String COL = "studentsinLibId";
32private static String COL1 = "StudentsinLibName";
33private static String COL2 = "studentsinLibNumber";
34
35private static final String[] COLUMNS = {COL,COL1,COL2};
36public Context context;
37
38public StudentssinLibDatabase(Context context) {
39    super(context, STUDENTDATABASETABLE_NAME, null, DATABASE_VERSION);
40    this.context=context;
41}
42@Override
43public void onCreate(SQLiteDatabase db) {
44
45    String CREATE_TABLE = "CREATE TABLE "+STUDENTDATABASETABLE_NAME+"("
46            +COL+" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
47            +COL1+" TEXT,"
48            +COL2+" TEXT);";
49
50    db.execSQL(CREATE_TABLE);
51}
52@Override
53public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
54    // Drop older students table if existed
55    db.execSQL("DROP TABLE IF EXISTS students");
56
57    // create fresh students table
58    this.onCreate(db);
59}
60public void addStudentstoLib(StudentsinLib studentstoLib){
61
62    Log.d("addStudent", studentstolib.toString());
63
64    // 1. get reference to writable DB
65    SQLiteDatabase db = this.getWritableDatabase();
66
67    // 2. create ContentValues to add key "column"/value
68
69    ContentValues values = new ContentValues();
70    values.put(COL, studentstolib.getId());
71    values.put(COL1, studentstolib.getName());
72    values.put(COL2, studentstolib.getNumber());
73
74    // 3. insert
75    db.insert(STUDENTDATABASETABLE_NAME, // table
76            null, //nullColumnHack
77            values); // key/value -> keys = column names/ values = column values
78
79    // 4. close
80    db.close();
81}
82public StudentsinLib getId(int id){
83
84    String selectQuery = "SELECT * FROM " + STUDENTDATABASETABLE_NAME + " WHERE "+ COL + " ="+id;
85
86    SQLiteDatabase db = this.getReadableDatabase(); // ======> the emulator points here
87    Cursor cursor = db.rawQuery(selectQuery, null);
88
89    if (cursor != null)
90        cursor.moveToFirst();
91
92    StudentsinLib studentsinLib = new StudentsinLib();
93    studentsinLib.setId(cursor.getInt(0));
94    studentsinLib.setName(cursor.getString(1));
95    studentsinLib.setNumber(cursor.getString(2));
96
97    //log
98    Log.d("getStudent(" + id + ")", StudentsinLib.toString());
99    // 5. return student
100    return studentsinLib;
101}
102
103public void deleteStudentinLib(int id){
104    SQLiteDatabase db = this.getWritableDatabase();
105    db.delete(StudentsinLibDatabase, COL + " = ?",
106            new String[]{String.valueOf(id)});
107    db.close();
108}
109
110public int updateStudent(StudentsinLib studentsinLib) {
111    // 1. get reference to writable DB
112    SQLiteDatabase db = this.getWritableDatabase();
113    // 2. create ContentValues to add key "column"/value
114    ContentValues values = new ContentValues();
115    values.put(COL, studentsinLib.getId());
116    values.put(COL1,studentsinLib.getName());
117    values.put(COL2,studentsinLib.getNumber());
118
119    // 3. updating row
120    int i = db.update(STUDENTDATABASETABLE_NAME, //table
121            values, // column/value
122            COL + " = ?", // selections
123            new String[]{String.valueOf(studentsinLib.getId())}); //selection args
124    // 4. close
125    db.close();
126    return i;
127}
128
129public ArrayList<StudentsinLib> getAllStudentsinLib() {
130    ArrayList<StudentsinLib> studentsinLibs = new ArrayList<StudentsinLib>();
131    // 1. build the query
132    String query = "SELECT * FROM " + STUDENTDATABASETABLE_NAME;
133    // 2. get reference to writable DB
134    SQLiteDatabase db = this.getWritableDatabase();
135    Cursor cursor = db.rawQuery(query, null);
136    // 3. go over each row, build student and add it to list
137    while (cursor.moveToNext()) {
138        StudentsinLib studentsinLib = new StudentsinLib();
139        studentsinLib.setId(cursor.getInt(0));
140        studentsinLib.setName(cursor.getString(1));
141        studentsinLib.setNumber(cursor.getString(2));
142        studentsinLibs.add(studentsinLib);
143    }
144    Log.d("getAllStudents()", studentsinLibs.toString());
145    // return student
146    return studentsinLibs;
147  }
148}