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https://issues.apache.org/jira/browse/HIVE-14159?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15472299#comment-15472299
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Lefty Leverenz commented on HIVE-14159:
---------------------------------------
Doc note: The *sort_array_by* UDF should be documented in the wiki for release
2.2.0. Added a TODOC2.2 label.
* [Hive Operators and UDFs -- Collection Functions |
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-CollectionFunctions]
Also, "sort_array_field" should be changed to "sort_array_by" in three examples
in this issue's description.
> sorting of tuple array using multiple field[s]
> ----------------------------------------------
>
> Key: HIVE-14159
> URL: https://issues.apache.org/jira/browse/HIVE-14159
> Project: Hive
> Issue Type: Improvement
> Components: UDF
> Reporter: Simanchal Das
> Assignee: Simanchal Das
> Labels: TODOC2.2, patch
> Fix For: 2.2.0
>
> Attachments: HIVE-14159.1.patch, HIVE-14159.2.patch,
> HIVE-14159.3.patch, HIVE-14159.4.patch
>
>
> Problem Statement:
> When we are working with complex structure of data like avro.
> Most of the times we are encountering array contains multiple tuples and each
> tuple have struct schema.
> Suppose here struct schema is like below:
> {noformat}
> {
> "name": "employee",
> "type": [{
> "type": "record",
> "name": "Employee",
> "namespace": "com.company.Employee",
> "fields": [{
> "name": "empId",
> "type": "int"
> }, {
> "name": "empName",
> "type": "string"
> }, {
> "name": "age",
> "type": "int"
> }, {
> "name": "salary",
> "type": "double"
> }]
> }]
> }
> {noformat}
> Then while running our hive query complex array looks like array of employee
> objects.
> {noformat}
> Example:
> //(array<struct<empId,empName,age,salary>>)
>
> Array[Employee(100,Foo,20,20990),Employee(500,Boo,30,50990),Employee(700,Harry,25,40990),Employee(100,Tom,35,70990)]
> {noformat}
> When we are implementing business use cases day to day life we are
> encountering problems like sorting a tuple array by specific field[s] like
> empId,name,salary,etc by ASC or DESC order.
> Proposal:
> I have developed a udf 'sort_array_by' which will sort a tuple array by one
> or more fields in ASC or DESC order provided by user ,default is ascending
> order .
> {noformat}
> Example:
> 1.Select
> sort_array_field(array[struct(100,Foo,20,20990),struct(500,Boo,30,50990),struct(700,Harry,25,40990),struct(100,Tom,35,70990)],"Salary","ASC");
> output:
> array[struct(100,Foo,20,20990),struct(700,Harry,25,40990),struct(500,Boo,30,50990),struct(100,Tom,35,70990)]
>
> 2.Select
> sort_array_field(array[struct(100,Foo,20,20990),struct(500,Boo,30,80990),struct(500,Boo,30,50990),struct(700,Harry,25,40990),struct(100,Tom,35,70990)],"Name","Salary","ASC");
> output:
> array[struct(500,Boo,30,50990),struct(500,Boo,30,80990),struct(100,Foo,20,20990),struct(700,Harry,25,40990),struct(100,Tom,35,70990)]
> 3.Select
> sort_array_field(array[struct(100,Foo,20,20990),struct(500,Boo,30,50990),struct(700,Harry,25,40990),struct(100,Tom,35,70990)],"Name","Salary","Age,"ASC");
> output:
> array[struct(500,Boo,30,50990),struct(500,Boo,30,80990),struct(100,Foo,20,20990),struct(700,Harry,25,40990),struct(100,Tom,35,70990)]
> {noformat}
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