[英]Hive UDF : Hive does not send proper arguments to UDF
这是我的 hive 表
CREATE TABLE `dum`(`val` map<string,array<string>>);
insert into dum select map('A',array('1','2','3'),'B',array('4','5','6'));
这就是它的外观
select * from dum;
{"A":["1","2","3"],"B":["4","5","6"]}
我正在尝试创建一个简单的 UDF,它可以将上述 map 的值中的所有项目组合成一个列表。 这是我想看到的
select modudf(val) from dum;
["1","2","3","4","5","6"]
所以我创造了
package some.package;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.udf.UDFType;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
@UDFType(deterministic = true)
public class CustomUDF extends UDF {
public List<String> evaluate(Map<String, String[]> inMap) {
ArrayList<String> res = new ArrayList<String>();
for(Map.Entry<String, String[]> ent : inMap.entrySet()){
for(String item : ent.getValue())
res.add(item);
}
return res;
}
}
但是当我尝试调用它时
add jar /path/to/my/jar;
CREATE TEMPORARY FUNCTION modudf AS 'some.package.CustomUDF';
select modudf(val) from dum;
我明白了
FAILED: SemanticException [Error 10014]: Line 1:7 Wrong arguments 'val': No matching method for class some.package.CustomUDF with (map<string,array<string>>). Possible choices: _FUNC_(map<struct<>,struct<>>)
为什么 hive 认为我的 UDF 需要map<struct<>,struct<>>
而不是map<string,array<string>>
? 我什至尝试用 Charsequence 替换 String 但我得到了同样的错误
请注意,根据文档
我应该能够使用 collections 作为evaluate
方法的输入
我究竟做错了什么?
更新
我还尝试了以下定义
public List<CharSequence> evaluate(Map<CharSequence, List<CharSequence>> inMap) {
modLogger.info(inMap);
ArrayList<CharSequence> res = new ArrayList<CharSequence>();
for(Map.Entry<CharSequence, List<CharSequence>> ent : inMap.entrySet()){
for(CharSequence item : ent.getValue())
res.add(item);
}
return res;
}
}
但我仍然得到
hive> add jar /path/to/my/jar;
Added [/path/to/my/jar] to class path
Added resources: [/path/to/my/jar]
hive> CREATE TEMPORARY FUNCTION modudf AS 'some.package.CustomUDF';
hive> desc dum;
OK
val map<string,array<string>>
Time taken: 0.094 seconds, Fetched: 1 row(s)
hive> select val from dum;
Query ID = root_20200629170147_80b5248f-4519-4dae-a070-3c5185f742ea
Total jobs = 1
Launching Job 1 out of 1
Status: Running (Executing on YARN cluster with App id application_1593449512239_0001)
----------------------------------------------------------------------------------------------
VERTICES MODE STATUS TOTAL COMPLETED RUNNING PENDING FAILED KILLED
----------------------------------------------------------------------------------------------
Map 1 .......... container SUCCEEDED 1 1 0 0 0 0
----------------------------------------------------------------------------------------------
VERTICES: 01/01 [==========================>>] 100% ELAPSED TIME: 6.12 s
----------------------------------------------------------------------------------------------
OK
{"A":["1","2","3"],"B":["4","5","6"]}
Time taken: 10.631 seconds, Fetched: 1 row(s)
hive> select modudf(val) from dum;
FAILED: SemanticException [Error 10014]: Line 1:7 Wrong arguments 'val': No matching method for class com.walmart.labs.search.sib.gcp.ModularTransformUDF with (map<string,array<string>>). Possible choices: _FUNC_(map<struct<>,array<struct<>>>)
查看您发送的链接中的引文:
请注意,Hive Arrays 在 Hive 中表示为列表。 因此,ARRAY 列将作为列表传入。
所以你应该有evaluate(Map<String, List<String>> inMap)
签名而不是evaluate(Map<String, String[]> inMap)
。
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