Question

I create a Class named MSqliteHelper to help me use the SQlite in android project

public class MSqliteHelper extends SQLiteOpenHelper{
private static final String DATABASE_NAME = "userData"; //dataBaseName
private static final int DATABASE_VERSION = 1;  
private SQLiteDatabase db;

public MSqliteHelper(Context context) { 
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    db = this.getWritableDatabase();
}

and I create the table like this

@Override
public void onCreate(SQLiteDatabase db) {

    String DATABASE_CREATE_TABLE =
        "create table userData ("
            + "HTTPorS TEXT,"
            + "IPHostName TEXT,"
            + "port TEXT,"
            + "userName TEXT,"
            + "password TEXT,"
            + "saveOption TEXT"
        + ");";
    db.execSQL(DATABASE_CREATE_TABLE);
}

and I can use this method to add whole row data

    public long create(String HTTPorS, String IPHostName, String port, String userName,     String password, String saveOption) {
    ContentValues args = new ContentValues();
    args.put("HTTPorS", HTTPorS);
    args.put("IPHostName", IPHostName);
    args.put("port", port);
    args.put("userName", userName);
    args.put("password", password);
    args.put("saveOption", saveOption);
    return db.insert("userData", null, args);
}

and i have a method to remove whole row data at index like this

    public int delete(long rowId) {
    return db.delete("userData",    
    "_ID=" + rowId,         
    null                
    );
}

but every times I call this delete method, the app crashed

and the wrong message is like this—–

E/AndroidRuntime(2976): android.database.sqlite.SQLiteException: no such column: _ID: , while compiling: DELETE FROM userData WHERE _ID=2

where did i do wrong ?

thanks for your help!

Answer 1

You have to create the table with _id in it. For example

String DATABASE_CREATE_TABLE =
    "create table userData ("
        + "_id INTEGER PRIMARY KEY AUTOINCREMENT,"
        + "HTTPorS TEXT,"
        + "IPHostName TEXT,"
        + "port TEXT,"
        + "userName TEXT,"
        + "password TEXT,"
        + "saveOption TEXT"
    + ");";