Sams Teach Yourself Microsoft® Windows® DNA Programming in 21 Days

Day 4

Quiz

1:	What is the relationship between table and entity?
A1:	A table contains information about an entity. An entity can be a person, a thing, a place, or an event.
2:	What is NULL?
A2:	NULL is a special value used to identify a missing value. You specify which columns can accept NULL values. Primary keys cannot contain NULLs.
3:	What are other names for record and field?
A3:	Another name for record is row. Another name for field is column.
4:	True/False. A primary key can only contain one column.
A4:	False. A primary key can contain many columns (in SQL Server, a primary key cannot exceed 256 bytes), although most tables have a primary key with a single column.
5:	What's a foreign key?
A5:	A foreign key occurs when a table has a ...