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

Appendix A: System Functions
RAND
The RAND function returns a random value between 0 and 1. The syntax is as follows:
RAND([])
The optional seed value is an integer expression, which specifies a start value to be used in random
number generation. You can allow SQL Server to generate its own random seed value each time you call
it, or you can specify your own.
ROUND
Be careful when specifying a literal seed value. Given a specific seed value, SQL Server will always
return the same result (meaning your RAND is suddenly not random at all). If you truly need a
random number generated, then either allow SQL Server to select a random seed for you, or use
a constantly changing seed such as the number of nanoseconds since a particular point in time.
The ROUND function takes a number specified in expression and rounds it to the specified length:
ROUND(, [, ])
The length parameter specifies the precision to which expression should be rounded. The length
parameter should be of the tinyint, smallint, or int data type. The optional function parameter
can be used to specify whether the number should be rounded or truncated. If a function value is
omitted or is equal to 0 (the default), the value in expression will be rounded. If any value other than 0
is provided, the value in expression will be truncated.
SIGN
SIN
The SIGN function returns the sign of the expression. The possible return values are +1 for a positive
number, 0 for zero, and -1 for a negative number. The syntax is as follows:
SIGN()
The SIN function returns the sine of an angle. The syntax is as follows:
SIN()
The angle should be in radians and must be of the float data type. The return value will also be of the
float data type.
SQRT
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The SQRT function returns the square root of the value given in expression. The syntax is as follows:
SQRT()