| /* |
| * 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 java.util.List; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlCall; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlIdentifier; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlKind; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlNode; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlOperator; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlSpecialOperator; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlWriter; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.parser.SqlParserPos; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.util.ImmutableNullableList; |
| |
| /** |
| * Parse tree for {@code UNIQUE}, {@code PRIMARY KEY} constraints. |
| * |
| * <p>And {@code FOREIGN KEY}, when we support it. |
| */ |
| public class SqlCheckConstraint extends SqlCall { |
| private static final SqlSpecialOperator OPERATOR = new SqlSpecialOperator("CHECK", SqlKind.CHECK); |
| |
| private final SqlIdentifier name; |
| private final SqlNode expression; |
| |
| /** Creates a SqlCheckConstraint; use {@link SqlDdlNodes#check}. */ |
| SqlCheckConstraint(SqlParserPos pos, SqlIdentifier name, SqlNode expression) { |
| super(pos); |
| this.name = name; // may be null |
| this.expression = expression; |
| } |
| |
| @Override |
| public SqlOperator getOperator() { |
| return OPERATOR; |
| } |
| |
| @Override |
| public List<SqlNode> getOperandList() { |
| return ImmutableNullableList.of(name, expression); |
| } |
| |
| @Override |
| public void unparse(SqlWriter writer, int leftPrec, int rightPrec) { |
| if (name != null) { |
| writer.keyword("CONSTRAINT"); |
| name.unparse(writer, 0, 0); |
| } |
| writer.keyword("CHECK"); |
| if (writer.isAlwaysUseParentheses()) { |
| expression.unparse(writer, 0, 0); |
| } else { |
| writer.sep("("); |
| expression.unparse(writer, 0, 0); |
| writer.sep(")"); |
| } |
| } |
| } |
| |
| // End SqlCheckConstraint.java |