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| - | <html><div align="center"><span style="color:red">DRAFT</span></div></html> | ||
| - | ====== Omnidex SQL Function: $RANDOM ====== | ||
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| + | ====== Omnidex SQL Function: $RANDOM ====== | ||
| ===== Description ===== | ===== Description ===== | ||
| - | Returns a pseudo-random number. The term "pseudo-random" is used as randomization is done using the Posix rand and srand functions. While these routines do provide satisfactory randomization for most applications, the numbers generated are not entirely random. | + | Returns a pseudo-random number. The term "pseudo-random" is used since randomization is done using the POSIX rand and srand functions. While these routines do provide satisfactory randomization for most applications, the numbers generated are not entirely random. |
| + | |||
| + | If seed is specified, it is used to start the random number generator. Note that only a single $random stream can be used in the process. If there are multiple $random functions in a select, only the first seed is used. Seed must be a literal. | ||
| + | |||
| + | This function returns an INTEGER datatype. | ||
| - | If seed is specified, it is used to start the random number generator. Note that only a single $random stream can be used in the process. If there are multiple $random functions in a select, only the first seed is used. Seed must be a literal. The return value is INTEGER length 4. | ||
| ===== Syntax ===== | ===== Syntax ===== | ||
| - | $RANDOM[(seed)] | ||
| - | == (seed) == | + | $RANDOM( numeric_expression [, seed] ) |
| - | Optional. Seed must be a literal. | + | == numeric_expression == |
| + | |||
| + | Required. Any expression that returns a numeric expression. | ||
| + | == seed == | ||
| + | Optional. A literal integer //n// is an integer indicating the number of digits to the right of the decimal. The default is 0. | ||
| + | |||
| ===== Example ===== | ===== Example ===== | ||
| - | ==== Example 1 ==== | + | ==== Example 1: $RANDOM without a seed ==== |
| - | $RANDOM(9) | + | |
| - | 68 | + | <code> |
| - | 6151 | + | |
| - | ... | + | > select $random rnd from $omnidex; |
| + | |||
| + | RND | ||
| + | ----------- | ||
| + | 1210253353 | ||
| + | </code> | ||
| + | |||
| + | ==== Example 2: $RANDOM with a seed ==== | ||
| + | |||
| + | <code> | ||
| + | > select $random(12345) rnd from $omnidex; | ||
| + | |||
| + | RND | ||
| + | ----------- | ||
| + | 1255939488 | ||
| + | </code> | ||
| + | |||
| + | ====== Additional Resources ====== | ||
| + | |||
| + | See also: | ||
| + | {{page>dev:sql:functions:see_also_math&noheader&nofooter&noeditbtn}} | ||
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