Increase the value of a record in android/sqlite database

Question

I try to increase the value of an integer key in a row in my table. However, nothing really seems to happen.

db.rawQuery("UPDATE table SET key = key + 1 WHERE name=?", new String[] {name});

However, this code works fine (just sets the key to a hard-coded value):

    ContentValues values = new ContentValues();
    values.put("key", 2);
    db.update("table", values, "name=?", new String[] {name});

Also tried '?' instead of just ?, but it resulted just in a run-time error.

Answer 1

From http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html:

public Cursor rawQuery (String sql, String[] selectionArgs)

Runs the provided SQL and returns a Cursor over the result set.

Returns A Cursor object, which is positioned before the first entry

compared to:

public void execSQL (String sql, Object[] bindArgs)

Execute a single SQL statement that is not a query. For example, CREATE TABLE, DELETE, INSERT, etc.

In other words, SQL queries which return a table are to be run with rawQuery, and those that do not return tables are to be run with execSQL