1 /*
2 * Copyright 2016-2025 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.mybatis.dynamic.sql;
17
18 import java.util.Objects;
19 import java.util.Optional;
20 import java.util.function.Supplier;
21
22 import org.jspecify.annotations.Nullable;
23
24 public abstract class AliasableSqlTable<T extends AliasableSqlTable<T>> extends SqlTable {
25
26 private @Nullable String tableAlias;
27 private final Supplier<T> constructor;
28
29 protected AliasableSqlTable(String tableName, Supplier<T> constructor) {
30 super(tableName);
31 this.constructor = Objects.requireNonNull(constructor);
32 }
33
34 public T withAlias(String alias) {
35 T newTable = constructor.get();
36 ((AliasableSqlTable<T>) newTable).tableAlias = alias;
37 newTable.tableName = tableName;
38 return newTable;
39 }
40
41 /**
42 * Returns a new instance of this table with the specified name. All column instances are recreated.
43 * This is useful for sharding where the table name may change at runtime based on some sharding algorithm,
44 * but all other table attributes are the same.
45 *
46 * @param name new name for the table
47 * @return a new AliasableSqlTable with the specified name, all other table attributes are copied
48 */
49 public T withName(String name) {
50 Objects.requireNonNull(name);
51 T newTable = constructor.get();
52 ((AliasableSqlTable<T>) newTable).tableAlias = tableAlias;
53 newTable.tableName = name;
54 return newTable;
55 }
56
57 @Override
58 public Optional<String> tableAlias() {
59 return Optional.ofNullable(tableAlias);
60 }
61 }