Cast, Convert and Parse

Question 1

What are some functions that can be used to apply explicit conversion?

Answer 1

1. CAST
2. CONVERT
3. PARSE
4. TRY_CAST
5. TRY_CONVERT
6. TRY_PARSE

SQL Server 70-461 02-02a

Question 2

What is the difference between the TRY and non TRY versions of the CAST, CONVERT and PARSE functions?

Answer 2

Those without the TRY fail if the value isn’t convertible, whereas those with the TRY return a NULL in such a case.

Forexample, the following code fails.
SELECT CAST(‘abc’ AS INT);

Conversely, the following code returns a NULL.
SELECT TRY_CAST(‘abc’ AS INT);

SQL Server 70-461 02-02a

Question 3

What is the proper syntax for the CAST function?

Answer 3

CAST( expression AS datatype [length] )

SQL Server 70-461 02-02a

Question 4

What is the proper syntax for the CONVERT function?

Answer 4

CONVERT ( data_type [length], expression [, style ] )

SQL Server 70-461 02-02a

Question 5

What is the proper syntax for the PARSE function?

Answer 5

PARSE (string_value AS data_type [ USING culture ] )

SQL Server 70-461 02-02a

Question 6

What is the difference between CAST, CONVERT and PARSE functions?

Answer 6

With CAST you indicate the expression and a target data type. With CONVERT there is a third optional Style argument. With PARSE there is a third optional Culture argument.

CAST( expression AS datatype [length] )
CONVERT(DATE, ‘1/2/2012’, 101)
PARSE(‘1/2/2012’ AS DATE USING ‘en–US’)

SQL Server 70-461 02-02a

Question 7

What does the optional Style argument in CONVERT represent?

Answer 7

The format used to convert between data types, such as a date format or string format.

You can:
- Convert datetime to character
- Convert float to real
- Convert money to character

Example of Style converting money to character:
Style of 0: No comma delimiters, 2 digits to the right of decimal (ie: 1234.56)

Style of 1: Comma delimiters, 2 digits to the right of decimal (ie: 1,234.56)

SQL Server 70-461 02-02a

Question 8

What does the optional Culture argument in PARSE represent?

Answer 8

Which culture to use that is supported by the .NET framework.

Ex.
en–US (English)
fr_FR (French)
ja_JP (Japanese)

SQL Server 70-461 02-02a