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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.shardingsphere.infra.binder.context.segment.select.projection.impl;
19  
20  import lombok.EqualsAndHashCode;
21  import lombok.Getter;
22  import lombok.RequiredArgsConstructor;
23  import lombok.ToString;
24  import org.apache.shardingsphere.infra.binder.context.segment.select.projection.Projection;
25  import org.apache.shardingsphere.sql.parser.statement.core.value.identifier.IdentifierValue;
26  
27  import java.util.Collection;
28  import java.util.LinkedList;
29  import java.util.Optional;
30  
31  /**
32   * Shorthand projection.
33   */
34  @RequiredArgsConstructor
35  @Getter
36  @EqualsAndHashCode
37  @ToString
38  public final class ShorthandProjection implements Projection {
39      
40      private final IdentifierValue owner;
41      
42      private final Collection<Projection> actualColumns;
43      
44      /**
45       * Get owner.
46       *
47       * @return owner
48       */
49      public Optional<IdentifierValue> getOwner() {
50          return Optional.ofNullable(owner);
51      }
52      
53      /**
54       * Get column projections.
55       *
56       * @return column projections
57       */
58      public Collection<ColumnProjection> getColumnProjections() {
59          Collection<ColumnProjection> result = new LinkedList<>();
60          for (Projection each : actualColumns) {
61              if (each instanceof ColumnProjection) {
62                  result.add((ColumnProjection) each);
63              }
64          }
65          return result;
66      }
67      
68      @Override
69      public String getColumnName() {
70          return null == owner ? "*" : owner.getValue() + ".*";
71      }
72      
73      @Override
74      public String getColumnLabel() {
75          return "*";
76      }
77      
78      @Override
79      public String getExpression() {
80          return null == owner ? "*" : owner.getValue() + ".*";
81      }
82      
83      @Override
84      public Optional<IdentifierValue> getAlias() {
85          return Optional.empty();
86      }
87  }