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Android Android Data Persistence Migrating a SQLite Database Adding a New Field

Where I have a mistake in this??

I all do how is been in video but don't understand where I have a mistake!

AlienSQLiteHelper.java
public class AlienSQLiteHelper extends SQLiteOpenHelper {

  public static final String DB_NAME = "aliens.db";
  public static final int DB_VERSION = 2;

  public static final String ALIENS_TABLE = "ALIENS";
  public static final String COLUMN_NAME = "NAME";
  public static final String COLUMN_TYPE = "TYPE";
  public static final String COLUMN_HOME_PLANET  = "HOME_PLANET";

  public static final String CREATE_ALIENS = "CREATE TABLE " + ALIENS_TABLE + " (" +
          "_id INTEGER PRIMARY KEY AUTOINCREMENT," +
          COLUMN_NAME + " TEXT, " +
          COLUMN_TYPE + " TEXT," + 
          COLUMN_HOME_PLANET + " TEXT)";

  public static final String DB_ALTER = "ALTER TABLE " + ALIENS_TABLE + " ADD COLUMN " + COLUMN_HOME_PLANET + "TEXT";

  public AlienSQLiteHelper(Context context) {
    super(context, DB_NAME, null, DB_VERSION);
  }

  @Override
  public void onCreate(SQLiteDatabase sqLiteDatabase) {
    sqLiteDatabase.execSQL(CREATE_ALIENS);
  }

  @Override
  public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
    switch (oldVersion) {
      case 1:
        database.execSQL(DB_ALTER);

    }
  }
}

5 Answers

Mazen Halawi
Mazen Halawi
7,806 Points

Your error should be onUpgrade method, you will need to DROP the table first and fire the onCreate function again.

Thanks you for help I found the mistake before!

Mazen Halawi
Mazen Halawi
7,806 Points

no problem, kindly mark it as solved so that other users move on.

cheers!

public class AlienSQLiteHelper extends SQLiteOpenHelper {

public static final String DB_NAME = "aliens.db"; public static final int DB_VERSION = 2;

public static final String ALIENS_TABLE = "ALIENS"; public static final String COLUMN_NAME = "NAME"; public static final String COLUMN_TYPE = "TYPE"; public static final String COLUMN_HOME_PLANET = "HOME_PLANET";

public static final String CREATE_ALIENS = "CREATE TABLE " + ALIENS_TABLE + " (" + "_id INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_NAME + " TEXT, " + COLUMN_TYPE + " TEXT, " + COLUMN_HOME_PLANET + "TEXT)";

// public static final String DB_ALTER = "ALTER TABLE " + ALIENS_TABLE + " ADD COLUMN " + COLUMN_HOME_PLANET ;

public static final String DB_ALTER = "ALTER TABLE " + ALIENS_TABLE + " ADD COLUMN " + COLUMN_HOME_PLANET + " TEXT ";

public AlienSQLiteHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); }

@Override public void onCreate(SQLiteDatabase sqLiteDatabase) { sqLiteDatabase.execSQL(CREATE_ALIENS); }

@Override public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) { switch (oldVersion) {
case 1:
database.execSQL(DB_ALTER); } } }

This code really work!