1. dual is a table that contains a single row.
2. The dual table has one VARCHAR2 column named dummy.
3. dual contains a single row with the value X.
desc dual; Name Null? Type DUMMY VARCHAR2(1)
时间: 2024-08-30 14:48:21
1. dual is a table that contains a single row.
2. The dual table has one VARCHAR2 column named dummy.
3. dual contains a single row with the value X.
desc dual; Name Null? Type DUMMY VARCHAR2(1)