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https://issues.apache.org/jira/browse/NIFI-1280?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15962170#comment-15962170
]
ASF GitHub Bot commented on NIFI-1280:
--------------------------------------
Github user olegz commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1652#discussion_r110541217
--- Diff:
nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/QueryFlowFile.java
---
@@ -0,0 +1,550 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.processors.standard;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Supplier;
+
+import org.apache.calcite.config.CalciteConnectionProperty;
+import org.apache.calcite.config.Lex;
+import org.apache.calcite.jdbc.CalciteConnection;
+import org.apache.calcite.schema.SchemaPlus;
+import org.apache.calcite.sql.parser.SqlParser;
+import org.apache.nifi.annotation.behavior.DynamicProperty;
+import org.apache.nifi.annotation.behavior.DynamicRelationship;
+import org.apache.nifi.annotation.behavior.EventDriven;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.InputRequirement.Requirement;
+import org.apache.nifi.annotation.behavior.SideEffectFree;
+import org.apache.nifi.annotation.behavior.SupportsBatching;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnScheduled;
+import org.apache.nifi.annotation.lifecycle.OnStopped;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.ValidationContext;
+import org.apache.nifi.components.ValidationResult;
+import org.apache.nifi.components.Validator;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.flowfile.attributes.CoreAttributes;
+import org.apache.nifi.processor.AbstractProcessor;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.ProcessorInitializationContext;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.io.OutputStreamCallback;
+import org.apache.nifi.queryflowfile.FlowFileTable;
+import org.apache.nifi.serialization.RecordSetWriter;
+import org.apache.nifi.serialization.RecordSetWriterFactory;
+import org.apache.nifi.serialization.RowRecordReaderFactory;
+import org.apache.nifi.serialization.WriteResult;
+import org.apache.nifi.serialization.record.ResultSetRecordSet;
+import org.apache.nifi.util.StopWatch;
+
+@EventDriven
+@SideEffectFree
+@SupportsBatching
+@Tags({"sql", "query", "calcite", "route", "record", "transform",
"select", "update", "modify", "etl", "filter", "record", "csv", "json", "logs",
"text", "avro", "aggregate"})
+@InputRequirement(Requirement.INPUT_REQUIRED)
+@CapabilityDescription("Evaluates one or more SQL queries against the
contents of a FlowFile. The result of the "
+ + "SQL query then becomes the content of the output FlowFile. This can
be used, for example, "
+ + "for field-specific filtering, transformation, and row-level
filtering. "
+ + "Columns can be renamed, simple calculations and aggregations
performed, etc. "
+ + "The Processor is configured with a Record Reader Controller Service
and a Record Writer service so as to allow flexibility in incoming and outgoing
data formats. "
+ + "The Processor must be configured with at least one user-defined
property. The name of the Property "
+ + "is the Relationship to route data to, and the value of the Property
is a SQL SELECT statement that is used to specify how input data should be
transformed/filtered. "
+ + "The SQL statement must be valid ANSI SQL and is powered by Apache
Calcite. "
+ + "If the transformation fails, the original FlowFile is routed to the
'failure' relationship. Otherwise, the data selected will be routed to the
associated "
+ + "relationship. See the Processor Usage documentation for more
information.")
+@DynamicRelationship(name="<Property Name>", description="Each
user-defined property defines a new Relationship for this Processor.")
+@DynamicProperty(name = "The name of the relationship to route data to",
value="A SQL SELECT statement that is used to determine what data should be
routed to this "
+ + "relationship.", supportsExpressionLanguage=true,
description="Each user-defined property specifies a SQL SELECT statement to run
over the data, with the data "
+ + "that is selected being routed to the relationship whose name is
the property name")
+public class QueryFlowFile extends AbstractProcessor {
+ static final PropertyDescriptor RECORD_READER_FACTORY = new
PropertyDescriptor.Builder()
+ .name("Record Reader")
+ .description("Specifies the Controller Service to use for parsing
incoming data and determining the data's schema")
+ .identifiesControllerService(RowRecordReaderFactory.class)
+ .required(true)
+ .build();
+ static final PropertyDescriptor RECORD_WRITER_FACTORY = new
PropertyDescriptor.Builder()
+ .name("Record Writer")
+ .description("Specifies the Controller Service to use for writing
results to a FlowFile")
+ .identifiesControllerService(RecordSetWriterFactory.class)
+ .required(true)
+ .build();
+ static final PropertyDescriptor INCLUDE_ZERO_RECORD_FLOWFILES = new
PropertyDescriptor.Builder()
+ .name("Include Zero Record FlowFiles")
+ .description("When running the SQL statement against an incoming
FlowFile, if the result has no data, "
+ + "this property specifies whether or not a FlowFile will be
sent to the corresponding relationship")
+ .expressionLanguageSupported(false)
+ .allowableValues("true", "false")
+ .defaultValue("true")
+ .required(true)
+ .build();
+ static final PropertyDescriptor CACHE_SCHEMA = new
PropertyDescriptor.Builder()
+ .name("Cache Schema")
+ .description("Parsing the SQL query and deriving the FlowFile's
schema is relatively expensive. If this value is set to true, "
+ + "the Processor will cache these values so that the Processor
is much more efficient and much faster. However, if this is done, "
+ + "then the schema that is derived for the first FlowFile
processed must apply to all FlowFiles. If all FlowFiles will not have the exact
"
+ + "same schema, or if the SQL SELECT statement uses the
Expression Language, this value should be set to false.")
+ .expressionLanguageSupported(false)
+ .allowableValues("true", "false")
+ .defaultValue("true")
+ .required(true)
+ .build();
+
+ public static final Relationship REL_ORIGINAL = new
Relationship.Builder()
+ .name("original")
+ .description("The original FlowFile is routed to this
relationship")
+ .build();
+ public static final Relationship REL_FAILURE = new
Relationship.Builder()
+ .name("failure")
+ .description("If a FlowFile fails processing for any reason (for
example, the SQL "
+ + "statement contains columns not present in input data), the
original FlowFile it will "
+ + "be routed to this relationship")
+ .build();
+
+ private List<PropertyDescriptor> properties;
+ private final Set<Relationship> relationships =
Collections.synchronizedSet(new HashSet<>());
+
+ private final Map<String, BlockingQueue<CachedStatement>>
statementQueues = new HashMap<>();
+
+ @Override
+ protected void init(final ProcessorInitializationContext context) {
+ try {
+ DriverManager.registerDriver(new
org.apache.calcite.jdbc.Driver());
+ } catch (final SQLException e) {
+ throw new ProcessException("Failed to load Calcite JDBC
Driver", e);
+ }
+
+ final List<PropertyDescriptor> properties = new ArrayList<>();
+ properties.add(RECORD_READER_FACTORY);
+ properties.add(RECORD_WRITER_FACTORY);
+ properties.add(INCLUDE_ZERO_RECORD_FLOWFILES);
+ properties.add(CACHE_SCHEMA);
+ this.properties = Collections.unmodifiableList(properties);
+
+ relationships.add(REL_FAILURE);
+ relationships.add(REL_ORIGINAL);
+ }
--- End diff --
Given that this code executes several times during the lifecycle of the
processor, consider static initializer.
> Create QueryFlowFile Processor
> ------------------------------
>
> Key: NIFI-1280
> URL: https://issues.apache.org/jira/browse/NIFI-1280
> Project: Apache NiFi
> Issue Type: Task
> Components: Extensions
> Reporter: Mark Payne
> Assignee: Mark Payne
> Fix For: 1.2.0
>
> Attachments: QueryFlowFile_Record_Reader-Writer_Examples.xml
>
>
> We should have a Processor that allows users to easily filter out specific
> columns from CSV data. For instance, a user would configure two different
> properties: "Columns of Interest" (a comma-separated list of column indexes)
> and "Filtering Strategy" (Keep Only These Columns, Remove Only These Columns).
> We can do this today with ReplaceText, but it is far more difficult than it
> would be with this Processor, as the user has to use Regular Expressions,
> etc. with ReplaceText.
> Eventually a Custom UI could even be built that allows a user to upload a
> Sample CSV and choose which columns from there, similar to the way that Excel
> works when importing CSV by dragging and selecting the desired columns? That
> would certainly be a larger undertaking and would not need to be done for an
> initial implementation.
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