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new 62786320eb5 [FLINK-28834][examples-table] Add temporal join example
and IT test
62786320eb5 is described below
commit 62786320eb555e36fe9fb82168fe97855dc54056
Author: qinjunjerry <[email protected]>
AuthorDate: Sat Aug 6 18:09:55 2022 +0200
[FLINK-28834][examples-table] Add temporal join example and IT test
This closes #20464
---
.../java/basics/TemporalJoinSQLExample.java | 196 +++++++++++++++++++++
.../java/basics/TemporalJoinSQLExampleITCase.java | 44 +++++
2 files changed, 240 insertions(+)
diff --git
a/flink-examples/flink-examples-table/src/main/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExample.java
b/flink-examples/flink-examples-table/src/main/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExample.java
new file mode 100644
index 00000000000..46361484e52
--- /dev/null
+++
b/flink-examples/flink-examples-table/src/main/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExample.java
@@ -0,0 +1,196 @@
+/*
+ * 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.flink.table.examples.java.basics;
+
+import org.apache.flink.streaming.api.datastream.DataStream;
+import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
+import org.apache.flink.table.api.DataTypes;
+import org.apache.flink.table.api.Schema;
+import org.apache.flink.table.api.Table;
+import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
+import org.apache.flink.table.connector.ChangelogMode;
+import org.apache.flink.types.Row;
+import org.apache.flink.types.RowKind;
+
+import java.time.Instant;
+
+/**
+ * Example for demonstrating the use of temporal join between a table backed
by a {@link DataStream}
+ * and a table backed by a change log stream.
+ *
+ * <p>In particular, the example shows how to
+ *
+ * <ul>
+ * <li>create a change log stream from elements
+ * <li>rename the table columns
+ * <li>register a table as a view under a name,
+ * <li>run a stream temporal join query on registered tables,
+ * <li>and convert the table back to a data stream.
+ * </ul>
+ *
+ * <p>The example executes a single Flink job. The results are written to
stdout.
+ */
+public class TemporalJoinSQLExample {
+
+ public static void main(String[] args) throws Exception {
+
+ // set up the Java DataStream API
+ final StreamExecutionEnvironment env =
StreamExecutionEnvironment.getExecutionEnvironment();
+
+ // set up the Java Table API
+ final StreamTableEnvironment tableEnv =
StreamTableEnvironment.create(env);
+
+ // Create a changelog stream of currency rate
+ final DataStream<Row> currencyRate =
+ env.fromElements(
+ Row.ofKind(RowKind.INSERT, Instant.ofEpochMilli(1000),
"USD", 0.8),
+ Row.ofKind(RowKind.UPDATE_AFTER,
Instant.ofEpochMilli(4000), "USD", 0.9),
+ Row.ofKind(RowKind.UPDATE_AFTER,
Instant.ofEpochMilli(3000), "USD", 1.0),
+ Row.ofKind(RowKind.UPDATE_AFTER,
Instant.ofEpochMilli(6000), "USD", 1.1));
+
+ // Create a table from change log stream
+ Table rateTable =
+ tableEnv.fromChangelogStream(
+ currencyRate,
+ Schema.newBuilder()
+ .column("f0",
DataTypes.TIMESTAMP_LTZ(3))
+ .column("f1",
DataTypes.STRING().notNull())
+ .column("f2", DataTypes.DOUBLE())
+ .watermark("f0", "f0 - INTERVAL '2'
SECONDS")
+ .primaryKey("f1")
+ .build(),
+ ChangelogMode.upsert())
+ .as("rate_time", "currency_code", "euro_rate");
+
+ // Register the table as a view, it will be accessible under a name
+ tableEnv.createTemporaryView("currency_rate", rateTable);
+
+ // Create a data stream of transaction
+ final DataStream<Transaction> transaction =
+ env.fromElements(
+ new Transaction("trx1", Instant.ofEpochMilli(1000),
"USD", 1),
+ new Transaction("trx2", Instant.ofEpochMilli(2000),
"USD", 1),
+ new Transaction("trx3", Instant.ofEpochMilli(3000),
"USD", 1),
+ new Transaction("trx4", Instant.ofEpochMilli(4000),
"USD", 1));
+
+ // convert the Transaction DataStream and register it as a view,
+ // it will be accessible under a name
+ Table trxTable =
+ tableEnv.fromDataStream(
+ transaction,
+ Schema.newBuilder()
+ .column("id", DataTypes.STRING())
+ .column("trxTime",
DataTypes.TIMESTAMP_LTZ(3))
+ .column("currencyCode",
DataTypes.STRING())
+ .column("amount", DataTypes.DOUBLE())
+ .watermark("trxTime", "trxTime -
INTERVAL '2' SECONDS")
+ .build())
+ .as("id", "trx_time", "currency_code", "amount");
+
+ // Register the table as a view, it will be accessible under a name
+ tableEnv.createTemporaryView("transaction", trxTable);
+
+ // temporal join the two tables
+ final Table result =
+ tableEnv.sqlQuery(
+ " SELECT\n"
+ + " t.id,\n"
+ + " t.trx_time,\n"
+ + " c.currency_code,\n"
+ + " t.amount,\n"
+ + " t.amount * c.euro_rate AS
total_euro\n"
+ + " FROM transaction t\n"
+ + " JOIN currency_rate FOR SYSTEM_TIME AS
OF t.trx_time AS c\n"
+ + " ON t.currency_code = c.currency_code;
");
+
+ // convert the Table back to an insert-only DataStream of type `Order`
+ tableEnv.toDataStream(result, EnrichedTransaction.class).print();
+
+ // after the table program is converted to a DataStream program,
+ // we must use `env.execute()` to submit the job
+ env.execute();
+ }
+
+ /** A simple class to represent a transaction. */
+ public static class Transaction {
+ public String id;
+ public Instant trxTime;
+ public String currencyCode;
+ // the rate comparing with euro
+ public double amount;
+
+ // for POJO detection in DataStream API
+ public Transaction() {}
+
+ // for structured type detection in Table API
+ public Transaction(String id, Instant trxTime, String currencyCode,
double amount) {
+ this.id = id;
+ this.trxTime = trxTime;
+ this.currencyCode = currencyCode;
+ this.amount = amount;
+ }
+
+ @Override
+ public String toString() {
+ return "Transaction{"
+ + "id="
+ + id
+ + ", trxTime="
+ + trxTime
+ + ", currencyCode='"
+ + currencyCode
+ + '\''
+ + ", amount="
+ + amount
+ + '}';
+ }
+ }
+
+ /** Enriched transaction by joining with the currency rate table. */
+ public static class EnrichedTransaction extends Transaction {
+ public double totalEuro;
+
+ // for POJO detection in DataStream API
+ public EnrichedTransaction() {}
+
+ // for structured type detection in Table API
+ public EnrichedTransaction(
+ String id, Instant trxTime, String currencyCode, double
amount, double totalEuro) {
+ super(id, trxTime, currencyCode, amount);
+ this.totalEuro = totalEuro;
+ }
+
+ @Override
+ public String toString() {
+ return "EnrichedTransaction{"
+ + "id="
+ + id
+ + ", trxTime="
+ + trxTime
+ + ", currencyCode='"
+ + currencyCode
+ + '\''
+ + ", amount="
+ + amount
+ + ", totalEuro="
+ + totalEuro
+ + '}';
+ }
+ }
+}
diff --git
a/flink-examples/flink-examples-table/src/test/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExampleITCase.java
b/flink-examples/flink-examples-table/src/test/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExampleITCase.java
new file mode 100644
index 00000000000..aee347313dc
--- /dev/null
+++
b/flink-examples/flink-examples-table/src/test/java/org/apache/flink/table/examples/java/basics/TemporalJoinSQLExampleITCase.java
@@ -0,0 +1,44 @@
+/*
+ * 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.flink.table.examples.java.basics;
+
+import org.apache.flink.table.examples.utils.ExampleOutputTestBase;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/** Test for Java {@link TemporalJoinSQLExample}. */
+public class TemporalJoinSQLExampleITCase extends ExampleOutputTestBase {
+
+ @Test
+ public void testExample() throws Exception {
+ TemporalJoinSQLExample.main(new String[0]);
+ final String consoleOutput = getOutputString();
+ assertThat(consoleOutput)
+ .contains(
+ "EnrichedTransaction{id=trx1,
trxTime=1970-01-01T00:00:01Z, currencyCode='USD', amount=1.0, totalEuro=0.8}")
+ .contains(
+ "EnrichedTransaction{id=trx2,
trxTime=1970-01-01T00:00:02Z, currencyCode='USD', amount=1.0, totalEuro=0.8}")
+ .contains(
+ "EnrichedTransaction{id=trx3,
trxTime=1970-01-01T00:00:03Z, currencyCode='USD', amount=1.0, totalEuro=1.0}")
+ .contains(
+ "EnrichedTransaction{id=trx4,
trxTime=1970-01-01T00:00:04Z, currencyCode='USD', amount=1.0, totalEuro=0.9}");
+ }
+}
