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https://issues.apache.org/jira/browse/FLINK-6891?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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sunjincheng updated FLINK-6891:
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Description:
LOG(X), LOG(B,X)
If called with one parameter, this function returns the natural logarithm of X.
If X is less than or equal to 0.0E0, the function returns NULL and (as of MySQL
5.7.4) a warning “Invalid argument for logarithm” is reported.
The inverse of this function (when called with a single argument) is the EXP()
function.
If called with two parameters, this function returns the logarithm of X to the
base B. If X is less than or equal to 0, or if B is less than or equal to 1,
then NULL is returned.
* Example:
LOG(2) -> 0.69314718055995
LOG(-2) -> NULL
LOG(2,65536) -> 16
LOG(10,100) -> 2
LOG(1,100) -> NULL
* See more:
** [MySQL|
https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html#function_log]
was:
LONG (N) A single parameter version of the function returns the natural
logarithm of N, and if two arguments are called, it returns any radix of the
logarithm of N.
* Syntax:
LOG ( float_expression [, base ] )
* Arguments
**float_expression: Is an expression of type float or of a type that can be
implicitly converted to float.
**base: Optional integer argument that sets the base for the logarithm.
* Return Types
float
* Example:
LOG(10) -> 2.30
* See more:
** [MSQL|https://docs.microsoft.com/en-us/sql/t-sql/functions/log-transact-sql]
** [MySQL|
https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html#function_log]
> Add LOG supported in SQL
> ------------------------
>
> Key: FLINK-6891
> URL: https://issues.apache.org/jira/browse/FLINK-6891
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Affects Versions: 1.4.0
> Reporter: sunjincheng
> Assignee: sunjincheng
>
> LOG(X), LOG(B,X)
> If called with one parameter, this function returns the natural logarithm of
> X. If X is less than or equal to 0.0E0, the function returns NULL and (as of
> MySQL 5.7.4) a warning “Invalid argument for logarithm” is reported.
> The inverse of this function (when called with a single argument) is the
> EXP() function.
> If called with two parameters, this function returns the logarithm of X to
> the base B. If X is less than or equal to 0, or if B is less than or equal to
> 1, then NULL is returned.
> * Example:
> LOG(2) -> 0.69314718055995
> LOG(-2) -> NULL
> LOG(2,65536) -> 16
> LOG(10,100) -> 2
> LOG(1,100) -> NULL
> * See more:
> ** [MySQL|
> https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html#function_log]
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