I am creating an app using SQLite.
It crashes before loading.
I fixed all viable errors and since I do not even get a log info, I am having troubles figuring out the error.
Please help.
SQLHelper
public class MySQLiteHelper extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "MediaDB";
// Media table name
private static final String TABLE_MEDIA = "media";
// Media Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_TYPE = "type";
private static final String KEY_TITLE = "title";
private static final String KEY_AUTHOR = "author";
private static final String[] COLUMNS = {KEY_ID,KEY_TYPE,KEY_TITLE,KEY_AUTHOR};
public MySQLiteHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
// SQL statement to create media table
String CREATE_MEDIA_TABLE = "CREATE TABLE media ( " +
"id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"tyoe TYPE, "+
"title TEXT, "+
"author TEXT )";
// create media table
db.execSQL(CREATE_MEDIA_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older media table if existed
db.execSQL("DROP TABLE IF EXISTS media");
// create fresh media table
this.onCreate(db);
}
//ADD MEDIA
public void addMedia(Media media){
//for logging
Log.d("addMedia", media.toString());
// get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put(KEY_TYPE, media.getType()); // get title
values.put(KEY_TITLE, media.getTitle()); // get title
values.put(KEY_AUTHOR, media.getAuthor()); // get author
// insert
db.insert(TABLE_MEDIA, // table
null, //nullColumnHack
values); // key/value -> keys = column names/ values = column values
// close
db.close();
}
//GET MEDIA
public Media getMedia(int id){
// get reference to readable DB
SQLiteDatabase db = this.getReadableDatabase();
// build query
Cursor cursor =
db.query(TABLE_MEDIA, // table
COLUMNS, // column names
" id = ?", // selections
new String[] { String.valueOf(id) }, // d. selections args
null, // group by
null, // having
null, // order by
null); // limit
// if we got results get the first one
if (cursor != null)
cursor.moveToFirst();
// build media object
Media media = new Media();
media.setId(Integer.parseInt(cursor.getString(0)));
media.setType(cursor.getString(1));
media.setTitle(cursor.getString(2));
media.setAuthor(cursor.getString(3));
//log
Log.d("getMedia("+id+")", media.toString());
// return media
return media;
}
//GET ALL MEDIA
public List<Media> getAllMedia() {
List<Media> medias = new LinkedList<Media>();
// build the query
String query = "SELECT * FROM " + TABLE_MEDIA;
// get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query, null);
// go over each row, build media and add it to list
Media media = null;
if (cursor.moveToFirst()) {
do {
media = new Media();
media.setId(Integer.parseInt(cursor.getString(0)));
media.setType(cursor.getString(1));
media.setTitle(cursor.getString(2));
media.setAuthor(cursor.getString(3));
// Add media to media
medias.add(media);
} while (cursor.moveToNext());
}
Log.d("getAllMedia()", medias.toString());
// return media
return medias;
}
//UPDATE
public int updateMedia(Media media) {
// get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put("type", media.getType()); // get title
values.put("title", media.getTitle()); // get title
values.put("author", media.getAuthor()); // get author
// updating row
int i = db.update(TABLE_MEDIA, //table
values, // column/value
KEY_ID+" = ?", // selections
new String[] { String.valueOf(media.getId()) }); //selection args
// close
db.close();
return i;
}
//DELETE
public void deleteMedia(Media media) {
// get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// delete
db.delete(TABLE_MEDIA, //table name
KEY_ID+" = ?", // selections
new String[] { String.valueOf(media.getId()) }); //selections args
// close
db.close();
//log
Log.d("deleteMedia", media.toString());
}
}
Media object class
public class Media {
private int id;
private String type;
private String title;
private String author;
public Media(){}
public Media(String type, String title, String author) {
super();
this.type = type;
this.title = title;
this.author = author;
}
//getters & setters
// getting ID
public int getId(){
return this.id;
}
// setting id
public void setId(int id){
this.id = id;
}
// getting type
public String getType(){
return this.type;
}
// setting title
public void setType(String type){
this.type = type;
}
// getting title
public String getTitle(){
return this.title;
}
// setting title
public void setTitle(String title){
this.title = title;
}
// getting author
public String getAuthor(){
return this.author;
}
// setting author
public void setAuthor(String author){
this.author = author;
}
@Override
public String toString() {
return "Media [id=" + id + ", type=" + type + ",title=" + title + ", author=" + author
+ "]";
}
}
Main Activity
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MySQLiteHelper db = new MySQLiteHelper(this);
/**
* CRUD Operations
* */
// add Media
db.addMedia(new Media("Book", "Android Application Development Cookbook", "Wei Meng Lee"));
db.addMedia(new Media("Book", "Android Programming: The Big Nerd Ranch Guide", "Bill Phillips and Brian Hardy"));
db.addMedia(new Media("Book", "Learn Android App Development", "Wallace Jackson"));
// get all media
List<Media> list = db.getAllMedia();
// delete one media
db.deleteMedia(list.get(0));
// get all media
db.getAllMedia();
}
}
There's an error in you table creation:
TYPE is not a valid SQLlite Data Type.
Please refer to this page: https://www.sqlite.org/datatype3.html
I'd write your table creation as