I want to use two tables in my SQLite database but when I try to read the second table my app crashes.
I have a table for the items in a storage and another table for the employees of the storage.
Here is my database class:
public class Database extends SQLiteOpenHelper {
protected static final String DATABASE_NAME = "Storage";
protected static final String KEY_ID = "id";
protected static final String KEY_DESCRIPTION = "description";
protected static final String KEY_CATEGORY = "category";
protected static final String KEY_ORIGIN = "origin";
protected static final String KEY_DATE = "date";
protected static final String KEY_BRAND = "brand";
protected static final String TAB_NAME = "items";
protected static final String KEY_ID2 = "id2";
protected static final String KEY_SURNAME = "surname";
protected static final String KEY_NAME = "name";
protected static final String KEY_USERNAME = "username";
protected static final String KEY_PASSWORD = "password";
protected static final String TAB_NAME2 = "employees";
protected static final int VERSION = 1;
public Database(Context context) {
super(context, DATABASE_NAME, null, VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TAB_NAME + " ("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_DESCRIPTION + " TEXT, "
+ KEY_CATEGORY + " TEXT, "
+ KEY_ORIGIN + " TEXT, "
+ KEY_DATE + " TEXT, "
+ KEY_BRAND + " TEXT)";
String CREATE_DIPENDENTI_TABLE = "CREATE TABLE " + TAB_NAME2 + " ("
+ KEY_ID2 + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_SURNAME + " TEXT, "
+ KEY_NAME + " TEXT, "
+ KEY_USERNAME + " TEXT, "
+ KEY_PASSWORD + " TEXT)";
db.execSQL(CREATE_ITEMS_TABLE);
db.execSQL(CREATE_DIPENDENTI_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TAB_NAME);
db.execSQL("DROP TABLE IF EXISTS " + TAB_NAME2);
this.onCreate(db);
}
public void Add(String des, String cat, String pro, String data, String brand) {
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_DESCRIPTION, des);
contentValues.put(KEY_CATEGORY, cat);
contentValues.put(KEY_ORIGIN, pro);
contentValues.put(KEY_DATE, data);
contentValues.put(KEY_BRAND, brand);
sqLiteDatabase.insert(TAB_NAME,null, contentValues);
sqLiteDatabase.close();
}
public void Add(String cog, String nom, String user, String pass) {
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_SURNAME, cog);
contentValues.put(KEY_NAME, nom);
contentValues.put(KEY_USERNAME, user);
contentValues.put(KEY_PASSWORD, pass);
sqLiteDatabase.insert(TAB_NAME2,null, contentValues);
sqLiteDatabase.close();
}
public Cursor getInfo() {
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + ";";
return sqLiteDatabase.rawQuery(query, null);
}
public ArrayList getInfoDip() {
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
ArrayList<String> al=new ArrayList<>();
Cursor cursor= sqLiteDatabase.rawQuery("SELECT * FROM " +TAB_NAME2, null);
cursor.moveToFirst();
while (!cursor.isAfterLast()){
al.add(cursor.getString(cursor.getColumnIndex("surname")));
al.add(cursor.getString(cursor.getColumnIndex("name")));
al.add(cursor.getString(cursor.getColumnIndex("username")));
al.add(cursor.getString(cursor.getColumnIndex("password")));
cursor.moveToNext();
}
return al;
}
public void Modify(int cod,String des, String cat, String pro, String dat, String bran){
SQLiteDatabase db = this.getWritableDatabase();
if(!des.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET description = "+"'"+des+"' "+ "WHERE id = "+"'"+cod+"'");
if(!cat.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET categoria = "+"'"+cat+"' "+ "WHERE id = "+"'"+cod+"'");
if(!pro.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET origin = "+"'"+pro+"' "+ "WHERE id = "+"'"+cod+"'");
if(!dat.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET date = "+"'"+dat+"' "+ "WHERE id = "+"'"+cod+"'");
if(!bran.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET brand = "+"'"+bran+"' "+ "WHERE id = "+"'"+cod+"'");
}
public void Modify(int cod, String cog, String nom, String user, String pass){
SQLiteDatabase db = this.getWritableDatabase();
if(!cog.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET surname = "+"'"+cog+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!nom.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET name = "+"'"+nom+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!user.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET username = "+"'"+user+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!pass.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET password = "+"'"+pass+"' "+ "WHERE id2 = "+"'"+cod+"'");
}
public void Delete(int cod){
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM "+TAB_NAME+" WHERE id= "+"'"+cod+"'");
}
public void DeleteDip(int cod){
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM "+TAB_NAME2+" WHERE id2= "+"'"+cod+"'");
}
public Cursor Search(int cod){
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + " WHERE id = "+"'"+cod+"';";
return sqLiteDatabase.rawQuery(query, null);
}
public Cursor Search(String des){
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + " WHERE description = "+"'"+des+"';";
return sqLiteDatabase.rawQuery(query, null);
}
public void DeleteAll() {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("delete from " + TAB_NAME);
}
}
and here is the activity where I try to get the ArrayList with the data:
private Database db= new Database(this);
private ArrayList<String> al=new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user);
db.Add("admin","admin","admin","admin");
al.addAll(db.getInfoDip());
But when I try to put the data in the ArrayList the app crashes. Can anyone help me out?
Well so far, how I learned that the best practice for formating queries is to use String.format function. Here your example:
String query = "SELECT * FROM " + TAB_NAME + ";";
Best practice:
String query = String.format("SELECT * FROM %s", TAB_NAME);
So let's get to the getInfoDip method, you should try this:
public List<ContentValues> getInfoDip() {
SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s", TAB_NAME2);
Cursor res = db.rawQuery(query, null);
res.moveToFirst();
List<ContentValues> list = new ArrayList<>(res.getCount());
while (!res.isAfterLast()){
String surname = res.getString(res.getColumnIndex(KEY_SURNAME));
String name = res.getString(res.getColumnIndex(KEY_NAME));
String username = res.getString(res.getColumnIndex(KEY_USERNAME));
String password = res.getString(res.getColumnIndex(KEY_PASSWORD));
list.add(new ContentValues(surname, name, username, password));
res.moveToNext();
}
return list;
}
Here is my whole SQLite test program, check out maybe it helps you:
package com.example.vezba09;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;
public class Database extends SQLiteOpenHelper {
private static final String DATABASE_FILE_NAME = "contact_database";
public Database(@Nullable Context context) {
super(context, DATABASE_FILE_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
String query = String.format(
"CREATE TABLE IF NOT EXISTS %s (%s INTEGER PRIMARY KEY AUTOINCREMENT, %s TEXT, %s TEXT, %s TEXT)",
ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID,
ContactModel.COLUMN_CONTACT_NAME,
ContactModel.COLUMN_CONTACT_EMAIL,
ContactModel.COLUMN_CONTACT_PHONE
);
db.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
String query = String.format("DROP TABLE IF EXISTS %s", ContactModel.TABLE_NAME);
db.execSQL(query);
onCreate(db);
}
//Dodavanje kontakta
public void addContact(String name, String email, String phone) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(ContactModel.COLUMN_CONTACT_NAME, name);
cv.put(ContactModel.COLUMN_CONTACT_EMAIL, email);
cv.put(ContactModel.COLUMN_CONTACT_PHONE, phone);
db.insert(ContactModel.TABLE_NAME, null, cv);
}
//Izmena
public void editContact(int contactId, String name, String email, String phone) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(ContactModel.COLUMN_CONTACT_NAME, name);
cv.put(ContactModel.COLUMN_CONTACT_EMAIL, email);
cv.put(ContactModel.COLUMN_CONTACT_PHONE, phone);
db.update(ContactModel.TABLE_NAME,
cv,
ContactModel.COLUMN_CONTACT_ID + "=?",
new String[]{String.valueOf(contactId)});
}
public int deleteContact(int contactId) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID + "=?",
new String[]{String.valueOf(contactId)});
}
public ContactModel getContactById(int contactId) {
SQLiteDatabase db = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s WHERE %s = ?",
ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID);
Cursor res = db.rawQuery(query, new String[] {String.valueOf(contactId)});
if(res.moveToFirst()) {
String name = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_NAME));
String email = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_EMAIL));
String phone = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_PHONE));
return new ContactModel(contactId, name, email, phone);
}
else {
return null;
}
}
public List<ContactModel> getAllContacts() {
SQLiteDatabase db = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s", ContactModel.TABLE_NAME);
Cursor res = db.rawQuery(query, null);
res.moveToFirst();
List<ContactModel> list = new ArrayList<>(res.getCount());
while(!res.isAfterLast()) {
int contactId = res.getInt(res.getColumnIndex(ContactModel.COLUMN_CONTACT_ID));
String name = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_NAME));
String email = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_EMAIL));
String phone = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_PHONE));
list.add(new ContactModel(contactId, name, email, phone));
res.moveToNext();
}
return list;
}
}
Try this and feel free to ask more questions :)
Best regards, Sanady