com.hazelcast.org.apache.calcite.tools.RelRunners Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
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package com.hazelcast.org.apache.calcite.tools;
import com.hazelcast.org.apache.calcite.interpreter.Bindables;
import com.hazelcast.org.apache.calcite.plan.RelOptTable;
import com.hazelcast.org.apache.calcite.rel.RelHomogeneousShuttle;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.RelShuttle;
import com.hazelcast.org.apache.calcite.rel.core.TableScan;
import com.hazelcast.org.apache.calcite.rel.logical.LogicalTableScan;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
/** Implementations of {@link RelRunner}. */
public class RelRunners {
private RelRunners() {}
/** Runs a relational expression by creating a JDBC connection. */
public static PreparedStatement run(RelNode rel) {
final RelShuttle shuttle = new RelHomogeneousShuttle() {
@Override public RelNode visit(TableScan scan) {
final RelOptTable table = scan.getTable();
if (scan instanceof LogicalTableScan
&& Bindables.BindableTableScan.canHandle(table)) {
// Always replace the LogicalTableScan with BindableTableScan
// because it's implementation does not require a "schema" as context.
return Bindables.BindableTableScan.create(scan.getCluster(), table);
}
return super.visit(scan);
}
};
rel = rel.accept(shuttle);
try (Connection connection = DriverManager.getConnection("jdbc:calcite:")) {
final RelRunner runner = connection.unwrap(RelRunner.class);
return runner.prepare(rel);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}