Identifiers

Question 1

What is an identifier?

Answer 1

It is a name for a table, attribute, schema or other object.

SQL Server 70-461 02-01

Question 2

What are the characteristics of a regular identifier?

Answer 2

1. The first character is one of the following:
   >a letter between a and z, lower or upper case.
   >underscore (_)
   >at sign (@)
   >number sign (#)
2. Subsequent characters can include:
   >letters
   >decimal numbers
   >underscore (_)
   >at sign (@)
   >number sign (#)
   >dollar sign ($)
3. A regular identifier cannot be a reserved word
4. A regular identifier cannot contain spaces
5. The identifier cannot include supplementary characters

SQL Server 70-461 02-01

Question 3

If an identifier doesn’t follow the rules for a regular identifier what kind of identifier is it and what must be done?

Answer 3

It is an irregular identifier and it must be delimited.

SQL Server 70-461 02-01

Question 4

Can a regular identifier be delimited?

Answer 4

A regular identifier can be delimited but it isn’t required to be delimited.

SQL Server 70-461 02-01

Question 5

In what ways can an irregular identifier be delimited?

Answer 5

1. With double quotation marks. Ex, “Sales”.”Orders”. This form is standard.
2. With square brackets. Ex, [Sales].[Orders]. This form is proprietary to T–SQL.

SQL Server 70-461 02-01

Question 6

What is the difference between a regular identifier and a delimited identifier

Answer 6

• Regular identifiers follow a set of rules
• Delimited identifiers do not follow the regular identifier rules and therefore must be surrounded by [ ] or “ “

SQL Server 70-461 08-01

Question 7

The [ ] or “ “ prefered as a delimiter?

Answer 7

• [ ]
• There is a setting that can be turned off in which case the code would not recognize “ “ as a delimiter.

SQL Server 70-461 08-01

Question 8

Can a regular identifier include spaces?

Answer 8

No

SQL Server 70-461 08-01

Question 9

What character must a regular identifier start with and what are the two exceptions?

Answer 9

• A letter or an underscore
• Variables must begin with @
• Temporary tables or procedures must start with #

SQL Server 70-461 08-01

Question 10

What can the length of an identifier be?

Answer 10

1 to 128 characters

SQL Server 70-461 08-01

Question 11

What are identifiers used for?

Answer 11

• tables names
• schema names
• column names
• variables
• temporary tables
• procedures
• etc

SQL Server 70-461 08-01

Question 12

For regular identifiers, what can the characters after the first character be?

Answer 12

• letters
• numerals
• @
• #
• $
• _

SQL Server 70-461 08-01

Question 13

What is best practice when naming identifiers?

Answer 13

1. Use regular identifiers
2. Even though you can use special characters, just use letters. numbers and underscores

SQL Server 70-461 08-01