GitHub user kevinyu98 opened a pull request: https://github.com/apache/spark/pull/19329
[SPARK-22110][SQL][Documentation] Add usage and improve documentation with arguments and examples for trim function ## What changes were proposed in this pull request? This PR proposes to enhance the documentation for `trim` functions in the function description session. - Add more `usage`, `arguments` and `examples` for the trim function - Adjust space in the `usage` session After the changes, the trim function documentation will look like this: - `trim` ```trim(str) - Removes the leading and trailing space characters from str. trim(BOTH trimStr FROM str) - Remove the leading and trailing trimStr characters from str trim(LEADING trimStr FROM str) - Remove the leading trimStr characters from str trim(TRAILING trimStr FROM str) - Remove the trailing trimStr characters from str Arguments: str - a string expression trimStr - the trim string characters to trim, the default value is a single space BOTH, FROM - these are keywords to specify trimming string characters from both ends of the string LEADING, FROM - these are keywords to specify trimming string characters from the left end of the string TRAILING, FROM - these are keywords to specify trimming string characters from the right end of the string Examples: > SELECT trim(' SparkSQL '); SparkSQL > SELECT trim('SL', 'SSparkSQLS'); parkSQ > SELECT trim(BOTH 'SL' FROM 'SSparkSQLS'); parkSQ > SELECT trim(LEADING 'SL' FROM 'SSparkSQLS'); parkSQLS > SELECT trim(TRAILING 'SL' FROM 'SSparkSQLS'); SSparkSQ ``` - `ltrim` ```ltrim ltrim(str) - Removes the leading space characters from str. ltrim(trimStr, str) - Removes the leading string contains the characters from the trim string Arguments: str - a string expression trimStr - the trim string characters to trim, the default value is a single space Examples: > SELECT ltrim(' SparkSQL '); SparkSQL > SELECT ltrim('Sp', 'SSparkSQLS'); arkSQLS ``` - `rtrim` ```rtrim rtrim(str) - Removes the trailing space characters from str. rtrim(trimStr, str) - Removes the trailing string which contains the characters from the trim string from the str Arguments: str - a string expression trimStr - the trim string characters to trim, the default value is a single space Examples: > SELECT rtrim(' SparkSQL '); SparkSQL > SELECT rtrim('LQSa', 'SSparkSQLS'); SSpark ``` This is the trim characters function jira: [trim function](https://issues.apache.org/jira/browse/SPARK-14878) ## How was this patch tested? Manually tested ``` spark-sql> describe function extended trim; 17/09/22 17:03:04 INFO CodeGenerator: Code generated in 153.026533 ms Function: trim Class: org.apache.spark.sql.catalyst.expressions.StringTrim Usage: trim(str) - Removes the leading and trailing space characters from `str`. trim(BOTH trimStr FROM str) - Remove the leading and trailing `trimStr` characters from `str` trim(LEADING trimStr FROM str) - Remove the leading `trimStr` characters from `str` trim(TRAILING trimStr FROM str) - Remove the trailing `trimStr` characters from `str` Extended Usage: Arguments: * str - a string expression * trimStr - the trim string characters to trim, the default value is a single space * BOTH, FROM - these are keywords to specify trimming string characters from both ends of the string * LEADING, FROM - these are keywords to specify trimming string characters from the left end of the string * TRAILING, FROM - these are keywords to specify trimming string characters from the right end of the string Examples: > SELECT trim(' SparkSQL '); SparkSQL > SELECT trim('SL', 'SSparkSQLS'); parkSQ > SELECT trim(BOTH 'SL' FROM 'SSparkSQLS'); parkSQ > SELECT trim(LEADING 'SL' FROM 'SSparkSQLS'); parkSQLS > SELECT trim(TRAILING 'SL' FROM 'SSparkSQLS'); SSparkSQ ``` ``` spark-sql> describe function extended ltrim; Function: ltrim Class: org.apache.spark.sql.catalyst.expressions.StringTrimLeft Usage: ltrim(str) - Removes the leading space characters from `str`. ltrim(trimStr, str) - Removes the leading string contains the characters from the trim string Extended Usage: Arguments: * str - a string expression * trimStr - the trim string characters to trim, the default value is a single space Examples: > SELECT ltrim(' SparkSQL '); SparkSQL > SELECT ltrim('Sp', 'SSparkSQLS'); arkSQLS ``` ``` spark-sql> describe function extended rtrim; Function: rtrim Class: org.apache.spark.sql.catalyst.expressions.StringTrimRight Usage: rtrim(str) - Removes the trailing space characters from `str`. rtrim(trimStr, str) - Removes the trailing string which contains the characters from the trim string from the `str` Extended Usage: Arguments: * str - a string expression * trimStr - the trim string characters to trim, the default value is a single space Examples: > SELECT rtrim(' SparkSQL '); SparkSQL > SELECT rtrim('LQSa', 'SSparkSQLS'); SSpark ``` You can merge this pull request into a Git repository by running: $ git pull https://github.com/kevinyu98/spark spark-14878-5 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/spark/pull/19329.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #19329 ---- commit 7ecbe4c28087564f1ba0adaa62a12cd28be351c0 Author: Kevin Yu <q...@us.ibm.com> Date: 2017-09-20T21:35:57Z adding examples for stringTrim string function commit 4f77d95cbd2492db0d398612dd28a0a89ea849fd Author: Kevin Yu <q...@us.ibm.com> Date: 2017-09-21T06:00:46Z adjust comments commit 0f3307dfc3dd21b3d643d3d58e9202743f958b23 Author: Kevin Yu <q...@us.ibm.com> Date: 2017-09-22T22:46:02Z rebase ---- --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org