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-> 3.141593 mysql> SELECT PI()+0.000000000000000000; -> 3.141592653589793116 

• POW( X , Y ) 

Returns the value of X  raised to the power of Y . 

mysql> SELECT POW(2,2); -> 4 mysql> SELECT POW(2,-2); -> 0.25 

• POWER( X , Y ) 

This is a synonym for POW() . 

• RADIANS( X ) 

Returns the argument X , converted from degrees to radians. (Note that π  radians equals 180 degrees.) 

mysql> SELECT RADIANS(90); -> 1.5707963267949 

• RAND([ N ]) 

Returns a random floating-point value v  in the range 0  <= v  < 1.0 . To obtain a random integer R  in the range i  <= R  < j , use the expression FLOOR( i  + RAND() * ( j − i )) . For example, to obtain a random integer in the range the range 7  <= R  < 12 , use the following statement: 

SELECT FLOOR(7 + (RAND() * 5)); 

If an integer argument N  is specified, it is used as the seed value: 

•With a constant initializer argument, the seed is initialized once when the statement is prepared, prior to execution. 

•With a nonconstant initializer argument (such as a column name), the seed is initialized with the value for each invocation of RAND() . 

One implication of this behavior is that for equal argument values, RAND( N )  returns the same value each time, and thus produces a repeatable sequence of column values. In the following example, the sequence of values produced by RAND(3)  is the same both places it occurs. 

mysql> CREATE TABLE t (i INT); Query OK, 0 rows affected (0.42 sec) mysql> INSERT INTO t VALUES(1),(2),(3); Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT i, RAND() FROM t; 

<img src='content_image/714393.jpg'>

mysql> SELECT i, RAND(3) FROM t; 

