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https://issues.apache.org/jira/browse/ARROW-17430?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17580288#comment-17580288
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Igor Suhorukov edited comment on ARROW-17430 at 8/16/22 12:18 PM:
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Thank you [~lidavidm] your approach works for manual coding for each dataset,
but org.apache.arrow.adapter.jdbc.JdbcParameterBinder.Builder is super useful
to reduce efforts to implement mapping of new type for dataset. The same
difference like develop program to process data or just allow end users to
write SQL querey
was (Author: JIRAUSER293905):
Thank you David Li your approach works for manual coding for each dataset, but
org.apache.arrow.adapter.jdbc.JdbcParameterBinder.Builder is super useful to
reduce efforts to implement mapping of new type for dataset. The same
difference like develop program to process data or just allow end users to
write SQL querey
> [Java] ListBinder to bind Arrow List type to DB column
> -------------------------------------------------------
>
> Key: ARROW-17430
> URL: https://issues.apache.org/jira/browse/ARROW-17430
> Project: Apache Arrow
> Issue Type: Improvement
> Components: Java
> Affects Versions: 10.0.0
> Reporter: Igor Suhorukov
> Priority: Major
>
> Typical real life Arrow datasets contain List type vectors of primitive type.
> Looks logically implement default JDBC parameter binders for such vector type
> or implement some kind on binder code extensibility of core framework via
> MetaINF/ServiceLocator
> Current implementation just [throws UnsupportedOperationException|#L80]]
>
> {code:java}
> @Override
>
>
> public ColumnBinder visit(ArrowType.List type) {
>
>
> throw new UnsupportedOperationException("No column binder
> implemented for type " + type);
>
>
> } {code}
>
> My current implementation patch {color:#000000}ColumnBinderArrowTypeVisitor
> in classpath to return ListBinder{color}
> {code:java}
> @Override
> public ColumnBinder visit(ArrowType.List type) {
> return new ListBinder((ListVector) vector);
> } {code}
> {color:#000000}and following code works for me with H2 database and in java
> stored PostgreSQL {color}{color:#000000}function in PL/Java to bind List
> parameter to JDBC:{color}
> {code:java}
> package org.apache.arrow.adapter.jdbc.binder;
> import org.apache.arrow.vector.complex.ListVector;
> import org.apache.arrow.vector.complex.impl.UnionListReader;
> import java.sql.PreparedStatement;
> import java.sql.SQLException;
> import java.sql.Types;
> import java.util.ArrayList;
> import java.util.Arrays;
> public class ListBinder extends BaseColumnBinder<ListVector>{
> private UnionListReader reader;
> public ListBinder(ListVector vector) {
> this(vector, Types.ARRAY);
> }
> public ListBinder(ListVector vector, int jdbcType) {
> super(vector, jdbcType);
> reader = vector.getReader();
> }
> @Override
> public void bind(PreparedStatement statement, int parameterIndex, int
> rowIndex) throws SQLException {
> reader.setPosition(rowIndex);
> ArrayList sourceArray = (ArrayList) reader.readObject();
> Class aClass = sourceArray.get(0).getClass();
> if(aClass.isAssignableFrom(Long.class)){
> Long[] res = new Long[sourceArray.size()];
> Arrays.setAll(res, sourceArray::get);
> statement.setObject(parameterIndex, res);
> } else
> if(aClass.isAssignableFrom(Integer.class)){
> Integer[] res = new Integer[sourceArray.size()];
> Arrays.setAll(res, sourceArray::get);
> statement.setObject(parameterIndex, res);
> } else
> if(aClass.isAssignableFrom(Short.class)){
> Short[] res = new Short[sourceArray.size()];
> Arrays.setAll(res, sourceArray::get);
> statement.setObject(parameterIndex, res);
> } else
> if(aClass.isAssignableFrom(String.class)){
> String[] res = new String[sourceArray.size()];
> Arrays.setAll(res, sourceArray::get);
> statement.setObject(parameterIndex, res);
> }
> }
> }
> {code}
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