在Android中，为什么不更新SQLite数据库？

Question

I'm attempting to update a row using:

myDatabase.update(DATABASE_TABLE, cvUpdate, KEY_NAME + "=" + mName, null);

but I get the following error:

ERROR/Database(282): Error updating persons_name=Bob using UPDATE peopleTable SET persons_name=? WHERE persons_name=Bob

I am using the following code to attempt the update:

public void updateEntry(String mName) throws SQLException {

    ContentValues cvUpdate = new ContentValues();
    cvUpdate.put(KEY_NAME, mName);
    ourDatabase.update(DATABASE_TABLE, cvUpdate, KEY_NAME + "=" + mName, null);

}

I have looked at other answers which seem to be similar to this problem but I have not found something definitive that solves the problem which I am having. It appears to be something to do with the variables but I may be completely wrong..

Answer 1

You're not enclosing your string in quotes. You're better off doing something like this:

ourDatabase.update(DATEABASE_TABLE, cvUpdate, KEY_NAME + "= ?", new String[]{mName});

when you use the above, it will automatically enclose the param in single-quotes if the type is a string.

Answer 2

“ persons_name = Bob”可能应该是“ persons_name ='Bob'”，因此请尝试：

ourDatabase.update(DATABASE_TABLE, cvUpdate, KEY_NAME + "='" + mName + "'", null);