Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Appendix A: System Functions
ASCII
❑ UNICODE
❑ UPPER
The ASCII function returns the ASCII code value of the leftmost character in character_expression.
The syntax is as follows:
CHAR
ASCII()
The CHAR function converts an ASCII code (specified in expression) into a string. The syntax is as follows:
CHAR()
The expression can be any integer between 0 and 255.
CHARINDEX
The CHARINDEX function returns the starting position of an expression in a character_string. The
syntax is as follows:
CHARINDEX(, [, ])
The expression parameter is the string, which is to be found. The character_string is the string to
be searched, usually a column. The start_location is the character position to begin the search, if this
is anything other than a positive number, the search will begin at the start of character_string.
DIFFERENCE
The DIFFERENCE function returns the difference between the SOUNDEX values of two expressions as an
integer. The syntax is as follows:
DIFFERENCE(, )
This function returns an integer value between 0 and 4. If the two expressions sound identical (for example,
blue and blew) a value of 4 will be returned. If there is no similarity, a value of 0 is returned.
LEFT
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The LEFT function returns the leftmost part of an expression, starting a specified number of characters
from the left. The syntax is as follows:
LEFT(, )
The expression parameter contains the character data from which the leftmost section will be extracted. The
integer parameter specifies the number of characters from the left to begin — it must be a positive integer.