[Isolated]

Use queries to select the information you want, then highlight it and depending on the version you are using you should be able to edit it, otherwise use UPDATE.

Код:

UPDATE `Table` SET `column` = value WHERE `Username` = `Username`;

or to select

Код:

SELECT * FROM `Table` WHERE `Username`;

That is using a wildcard, if you want to use it without that's fine just enter the column name.