How do I clear a SQLite database field?

Question

Probably a really simple question, but I have a table in which a column is not set by default. The user can set the contents of that field, which works fine, but they should also be able to clear the field. How do I reset the db field? Its affinity is real . Do I set an empty string in the field? Null? Thanks.

Answer 1

您可以使用ContentValues.putNull（java.lang.String）

ContentValues args = new ContentValues();

args.putNull(KEY_RISK_AMOUNT);

Answer 2

Simply:

UPDATE myTable SET myField = NULL

It (quite obviously) requires that myField is NULLABLE.