/* * 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.calcite.schema.impl; import org.apache.calcite.adapter.java.AbstractQueryableTable; import org.apache.calcite.jdbc.CalciteSchema; import org.apache.calcite.linq4j.QueryProvider; import org.apache.calcite.linq4j.Queryable; import org.apache.calcite.plan.RelOptTable; import org.apache.calcite.plan.RelOptUtil; import org.apache.calcite.rel.RelNode; import org.apache.calcite.rel.RelRoot; import org.apache.calcite.rel.RelShuttleImpl; import org.apache.calcite.rel.core.TableScan; import org.apache.calcite.rel.type.RelDataType; import org.apache.calcite.rel.type.RelDataTypeFactory; import org.apache.calcite.rel.type.RelProtoDataType; import org.apache.calcite.schema.Schema; import org.apache.calcite.schema.SchemaPlus; import org.apache.calcite.schema.TranslatableTable; import com.google.common.collect.ImmutableList; import java.lang.reflect.Type; import java.util.List; /** * Table whose contents are defined using an SQL statement. * * <p>It is not evaluated; it is expanded during query planning.</p> */ public class ViewTable extends AbstractQueryableTable implements TranslatableTable { private final String viewSql; private final List<String> schemaPath; private final RelProtoDataType protoRowType; private final List<String> viewPath; public ViewTable(Type elementType, RelProtoDataType rowType, String viewSql, List<String> schemaPath, List<String> viewPath) { super(elementType); this.viewSql = viewSql; this.schemaPath = ImmutableList.copyOf(schemaPath); this.protoRowType = rowType; this.viewPath = viewPath == null ? null : ImmutableList.copyOf(viewPath); } @Deprecated // to be removed before 2.0 public static ViewTableMacro viewMacro(SchemaPlus schema, final String viewSql, final List<String> schemaPath) { return viewMacro(schema, viewSql, schemaPath, null, Boolean.TRUE); } @Deprecated // to be removed before 2.0 public static ViewTableMacro viewMacro(SchemaPlus schema, String viewSql, List<String> schemaPath, Boolean modifiable) { return viewMacro(schema, viewSql, schemaPath, null, modifiable); } /** Table macro that returns a view. * * @param schema Schema the view will belong to * @param viewSql SQL query * @param schemaPath Path of schema * @param modifiable Whether view is modifiable, or null to deduce it */ public static ViewTableMacro viewMacro(SchemaPlus schema, String viewSql, List<String> schemaPath, List<String> viewPath, Boolean modifiable) { return new ViewTableMacro(CalciteSchema.from(schema), viewSql, schemaPath, viewPath, modifiable); } /** Returns the view's SQL definition. */ public String getViewSql() { return viewSql; } /** Returns the the schema path of the view. */ public List<String> getSchemaPath() { return schemaPath; } /** Returns the the path of the view. */ public List<String> getViewPath() { return viewPath; } @Override public Schema.TableType getJdbcTableType() { return Schema.TableType.VIEW; } public RelDataType getRowType(RelDataTypeFactory typeFactory) { return protoRowType.apply(typeFactory); } public <T> Queryable<T> asQueryable(QueryProvider queryProvider, SchemaPlus schema, String tableName) { return queryProvider.createQuery( getExpression(schema, tableName, Queryable.class), elementType); } public RelNode toRel( RelOptTable.ToRelContext context, RelOptTable relOptTable) { return expandView(context, relOptTable.getRowType(), viewSql).rel; } private RelRoot expandView(RelOptTable.ToRelContext context, RelDataType rowType, String queryString) { try { final RelRoot root = context.expandView(rowType, queryString, schemaPath, viewPath); final RelNode rel = RelOptUtil.createCastRel(root.rel, rowType, true); // Expand any views final RelNode rel2 = rel.accept( new RelShuttleImpl() { @Override public RelNode visit(TableScan scan) { final RelOptTable table = scan.getTable(); final TranslatableTable translatableTable = table.unwrap(TranslatableTable.class); if (translatableTable != null) { return translatableTable.toRel(context, table); } return super.visit(scan); } }); return root.withRel(rel2); } catch (Exception e) { throw new RuntimeException("Error while parsing view definition: " + queryString, e); } } }