What does nullColumnHack means? [duplicate]

Question

According to the SQLiteDatabase API documentation:

• insert(String table, String nullColumnHack, ContentValues values)

  Convenience method for inserting a row into the database.

What does nullColumnHack means?

Can you give me an example?

Answer 1

Sometimes you want to insert an empty row, in that case ContentValues have no content value, and you should use nullColumnHack.

For example, you want to insert an empty row into a table student(id, name), which id is auto generated and name is null. You could invoke like this:

ContentValues cv = new ContentValues();
db.insert("student", "name", cv);