kennknowles commented on code in PR #36509: URL: https://github.com/apache/beam/pull/36509#discussion_r2542574412
########## sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/parser/SqlShowDatabases.java: ########## @@ -0,0 +1,134 @@ +/* + * 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.beam.sdk.extensions.sql.impl.parser; + +import static org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.util.Static.RESOURCE; + +import java.util.Collection; +import java.util.Collections; +import java.util.List; +import java.util.stream.Collectors; +import org.apache.beam.sdk.extensions.sql.impl.BeamCalciteSchema; +import org.apache.beam.sdk.extensions.sql.impl.CatalogManagerSchema; +import org.apache.beam.sdk.extensions.sql.impl.CatalogSchema; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.jdbc.CalcitePrepare; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.runtime.SqlFunctions; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.schema.Schema; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlCall; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlIdentifier; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlKind; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlNode; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlOperator; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlSpecialOperator; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.SqlUtil; +import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.sql.parser.SqlParserPos; +import org.checkerframework.checker.nullness.qual.Nullable; + +public class SqlShowDatabases extends SqlCall implements BeamSqlParser.ExecutableStatement { + private static final SqlOperator OPERATOR = + new SqlSpecialOperator("SHOW DATABASES", SqlKind.OTHER_DDL); + + private final boolean showCurrentOnly; + private final @Nullable SqlIdentifier catalogName; + private final @Nullable SqlNode regex; + + public SqlShowDatabases( + SqlParserPos pos, + boolean showCurrentOnly, + @Nullable SqlIdentifier catalogName, + @Nullable SqlNode regex) { + super(pos); + this.showCurrentOnly = showCurrentOnly; + this.catalogName = catalogName; + this.regex = regex; + } + + @Override + public List<SqlNode> getOperandList() { + return Collections.emptyList(); + } + + @Override + public SqlOperator getOperator() { + return OPERATOR; + } + + @Override + public void execute(CalcitePrepare.Context context) { + Schema schema = SqlDdlNodes.schema(context, true).schema; + + if (!(schema instanceof CatalogManagerSchema)) { + throw SqlUtil.newContextException( + pos, + RESOURCE.internal( + "Attempting to execute 'SHOW DATABASES' with unexpected Calcite Schema of type " + + schema.getClass())); + } + + CatalogSchema catalogSchema; + if (catalogName != null) { + String catalog = catalogName.toString(); + catalogSchema = ((CatalogManagerSchema) schema).getCatalogSchema(catalog); + } else { + catalogSchema = ((CatalogManagerSchema) schema).getCurrentCatalogSchema(); + } + + if (showCurrentOnly) { + @Nullable BeamCalciteSchema currentDatabase = catalogSchema.getCurrentDatabaseSchema(); + String output = + currentDatabase == null ? "No database is currently set" : currentDatabase.name(); + System.out.println(output); + return; + } + Collection<String> databases = catalogSchema.databases(); + print(databases, catalogSchema.getCatalog().name(), SqlDdlNodes.getString(regex)); + } + + private static void print(Collection<String> databases, String path, @Nullable String pattern) { + SqlFunctions.LikeFunction calciteLike = new SqlFunctions.LikeFunction(); + + final String headerName = "Databases in " + path; + final String separatorChar = "-"; + + int nameWidth = headerName.length(); + + for (String dbName : databases) { + nameWidth = Math.max(nameWidth, dbName.length()); + } + + nameWidth += 2; + String format = "| %-" + nameWidth + "s |%n"; + + int separatorWidth = nameWidth + 2; + String separator = + String.format( + "+" + new String(new char[separatorWidth]).replace("\0", separatorChar) + "+%n"); + + System.out.printf(separator); + System.out.printf(format, headerName); + System.out.printf(separator); + if (databases != null) { + for (String dbName : databases.stream().sorted().collect(Collectors.toList())) { + if (pattern == null || calciteLike.like(dbName, pattern)) { + System.out.printf(format, dbName); + } + } + } Review Comment: This comment is correct. You already have a loop over this variable above. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
