flink-libraries/flink-sql-parser/src/main/java/org/apache/flink/sql/parser/ddl/SqlCreateView.java

/*
 * 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.sql.parser.ddl;

import org.apache.flink.shaded.guava18.com.google.common.collect.ImmutableList;
import org.apache.flink.shaded.guava18.com.google.common.collect.Lists;

import org.apache.calcite.sql.SqlCall;
import org.apache.calcite.sql.SqlIdentifier;
import org.apache.calcite.sql.SqlKind;
import org.apache.calcite.sql.SqlLiteral;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.SqlNodeList;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.SqlSpecialOperator;
import org.apache.calcite.sql.SqlWriter;
import org.apache.calcite.sql.parser.SqlParserPos;

import java.util.List;

/**
 * CREATE VIEW DDL sql call.
 */
public class SqlCreateView extends SqlCall {

	public static final SqlSpecialOperator OPERATOR = new SqlSpecialOperator("CREATE_VIEW", SqlKind.CREATE_VIEW) {
		@Override
		public SqlCall createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) {
			return new SqlCreateView(pos, (SqlIdentifier) operands[0], (SqlNodeList) operands[1], operands[2], (SqlLiteral) operands[3]);
		}
	};

	private SqlIdentifier viewName;
	private SqlNodeList fieldList;
	private SqlNode query;
	private boolean replaceView;
	private String subQuerySql;

	public SqlCreateView(
		SqlParserPos pos,
		SqlIdentifier viewName,
		SqlNodeList fieldList,
		SqlNode query,
		SqlLiteral replaceView) {

		this(pos, viewName, fieldList, query, replaceView.booleanValue());
	}

	public SqlCreateView(
		SqlParserPos pos,
		SqlIdentifier viewName,
		SqlNodeList fieldList,
		SqlNode query,
		boolean replaceView) {

		super(pos);
		this.viewName = viewName;
		this.query = query;
		this.replaceView = replaceView;
		this.fieldList = fieldList;
	}

	@Override
	public SqlOperator getOperator() {
		return OPERATOR;
	}

	@Override
	public List<SqlNode> getOperandList() {
		List<SqlNode> ops = Lists.newArrayList();
		ops.add(viewName);
		ops.add(fieldList);
		ops.add(query);
		ops.add(SqlLiteral.createBoolean(replaceView, SqlParserPos.ZERO));
		return ops;
	}

	@Override
	public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
		writer.keyword("CREATE");
		if (replaceView) {
			writer.keyword("OR");
			writer.keyword("REPLACE");
		}
		writer.keyword("VIEW");
		viewName.unparse(writer, leftPrec, rightPrec);
		if (fieldList.size() > 0) {
			writer.keyword("(");
			fieldList.get(0).unparse(writer, leftPrec, rightPrec);
			for (int i = 1; i < fieldList.size(); i++) {
				writer.keyword(",");
				fieldList.get(i).unparse(writer, leftPrec, rightPrec);
			}
			writer.keyword(")");
		}
		writer.keyword("AS");
		query.unparse(writer, leftPrec, rightPrec);
	}

	public List<String> getSchemaPath() {
		if (viewName.isSimple()) {
			return ImmutableList.of();
		}

		return viewName.names.subList(0, viewName.names.size() - 1);
	}

	public String getName() {
		if (viewName.isSimple()) {
			return viewName.getSimple();
		}

		return viewName.names.get(viewName.names.size() - 1);
	}

	public List<String> getFieldNames() {
		List<String> fieldNames = Lists.newArrayList();
		for (SqlNode node : fieldList.getList()) {
			fieldNames.add(node.toString());
		}
		return fieldNames;
	}

	public SqlNode getQuery() {
		return query;
	}

	public boolean getReplace() {
		return replaceView;
	}

	public String getSubQuerySql() {
		return subQuerySql;
	}

	public void setSubQuerySql(String subQuerySql) {
		this.subQuerySql = subQuerySql;
	}

	public void validate() {
		//todo:
	}

}