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https://issues.apache.org/jira/browse/BEAM-7425?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Kishan Kumar updated BEAM-7425:
-------------------------------
Summary: Reading BigQuery Table Data into Java Classes(Pojo) Directly
(was: Reading BigQuery Table Data in for of Java Classes(Pojo))
> Reading BigQuery Table Data into Java Classes(Pojo) Directly
> ------------------------------------------------------------
>
> Key: BEAM-7425
> URL: https://issues.apache.org/jira/browse/BEAM-7425
> Project: Beam
> Issue Type: New Feature
> Components: beam-model
> Affects Versions: 2.12.0
> Environment: Dataflow
> Reporter: Kishan Kumar
> Priority: Major
> Labels: newbie, patch
> Fix For: 2.13.0
>
>
> While Developing my code I used the below code snippet to read the table data
> from BigQuery.
> {{PCollection<ReasonCode> gpseEftReasonCodes = input. apply("Reading xxyyzz",
> BigQueryIO.read(new ReadTable<ReasonCode>(ReasonCode.class))
> .withoutValidation().withTemplateCompatibility() .fromQuery("Select * from
> dataset.xxyyzz").usingStandardSql()
> .withCoder(SerializableCoder.of(xxyyzz.class)) }}
> *Read Table Class:*
> {{@DefaultSchema(JavaBeanSchema.class) }}
> {{public class ReadTable<T> implements SerializableFunction<SchemaAndRecord,
> T> {}}
> {{ private static final long serialVersionUID = 1L; }}
> {{private static Gson gson = new Gson(); }}
> {{public static final Logger LOG = LoggerFactory.getLogger(ReadTable.class);
> private final Counter countingRecords =
> Metrics.counter(ReadTable.class,"Reading Records EFT Report"); }}
> {{private Class<T> class1; public ReadTable(Class<T> class1) {}}
> {{ this.class1 = class1; }}
> {{} }}
> {{public T apply(SchemaAndRecord schemaAndRecord) {}}
> {{ Map<String, String> mapping = new HashMap<>(); }}
> {{int counter = 0; }}
> {{try { }}
> {{GenericRecord s = schemaAndRecord.getRecord(); }}
> {{org.apache.avro.Schema s1 = s.getSchema(); }}
> {{for (Field f : s1.getFields()) { }}
> {{counter++; mapping.put(f.name(),
> null==s.get(f.name())?null:String.valueOf(s.get(counter))); }}
> {{}}}
> {{ countingRecords.inc(); }}
> {{JsonElement jsonElement = gson.toJsonTree(mapping); }}
> {{return gson.fromJson(jsonElement, class1); }}
> {{}catch(Exception mp) { }}
> {{LOG.error("Found Wrong Mapping for the Record: "+mapping);
> mp.printStackTrace(); return null; } } } }}
> So After Reading the data from Bigquery I was mapping data from
> SchemaAndRecord to pojo I was getting value for columns whose Data type is
> Numeric mention below.
> *{{last_update_amount=java.nio.HeapByteBuffer[pos=0 lim=16 cap=16]}}*
> My Expectation was I will get exact value but getting the HyperByte Buffer
> the version I am using is Apache beam 2.12.0. If any more information is
> needed then please let me know.
> Way 2 Tried:
> {{GenericRecord s = schemaAndRecord.getRecord(); }}
> {{org.apache.avro.Schema s1 = s.getSchema(); }}
> {{for (Field f : s1.getFields()) { }}
> {{counter++; mapping.put(f.name(),
> null==s.get(f.name())?null:String.valueOf(s.get(counter)));
> if(f.name().equalsIgnoreCase("reason_code_id")) { }}
> {{BigDecimal numericValue = new Conversions.DecimalConversion()
> .fromBytes((ByteBuffer)s.get(f.name()) , }}
> {{Schema.create(s1.getType()), s1.getLogicalType());
> System.out.println("Numeric Con"+numericValue); } else \{
> System.out.println("Else Condition "+f.name()); } } ``` }}
> {{Facing Issue: }}
> {{2019-05-24 (14:10:37) org.apache.avro.AvroRuntimeException: Can't create a:
> RECORD}}
>
> {{It would be Great if we have a method which map all the BigQuery Data with
> Pojo Schema which Means if i have 10 Columns in BQ and in my Pojo i need only
> 5 Column then in that case BigQueryIO should map only that 5 Data values and
> Rest will be Rejected As i am Doing After So much Effort. Numeric Data Type
> must be Deserialize by it self while fetching data like TableRow.}}
>
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