問題文
A load inserts a zero length string into a character column and a later query that keeps the rows where that column is not empty leaves those rows out. Which statement describes the behavior and the advice around it?
選択肢
- A character value of zero length is padded to one blank so the rows hold a space and the test compares that space with the empty value.
- A character value of zero length is currently treated as a null so the rows fall out of that test and Oracle advises against relying on the equivalence.
- A character value of zero length is rejected by the column so the load must have failed and the rows in question never reached the table.
- A character value of zero length is stored as a value of its own so the rows should have passed that test and the load must have inserted a null.