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.sql.JDBCType;
19 import java.util.Optional;
20
21 import org.mybatis.dynamic.sql.render.RenderingContext;
22 import org.mybatis.dynamic.sql.render.RenderingStrategy;
23 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
24
25 /**
26 * Describes attributes of columns that are necessary for rendering if the column is not expected to
27 * be bound as a JDBC parameter. Columns in select lists, join expressions, and group by expressions
28 * are typically not bound.
29 *
30 * @author Jeff Butler
31 */
32 public interface BasicColumn {
33
34 /**
35 * Returns the columns alias if one has been specified.
36 *
37 * @return the column alias
38 */
39 Optional<String> alias();
40
41 /**
42 * Returns a new instance of a BasicColumn with the alias set.
43 *
44 * @param alias
45 * the column alias to set
46 *
47 * @return new instance with alias set
48 */
49 BasicColumn as(String alias);
50
51 /**
52 * Returns a rendering of the column.
53 * The rendered fragment should include the table alias based on the TableAliasCalculator
54 * in the RenderingContext. The fragment could contain prepared statement parameter
55 * markers and associated parameter values if desired.
56 *
57 * @param renderingContext the rendering context (strategy, sequence, etc.)
58 * @return a rendered SQL fragment and, optionally, parameters associated with the fragment
59 * @since 1.5.1
60 */
61 FragmentAndParameters render(RenderingContext renderingContext);
62
63 default Optional<JDBCType> jdbcType() {
64 return Optional.empty();
65 }
66
67 default Optional<String> typeHandler() {
68 return Optional.empty();
69 }
70
71 default Optional<RenderingStrategy> renderingStrategy() {
72 return Optional.empty();
73 }
74
75 /**
76 * Utility method to make it easier to build column lists for methods that require an
77 * array rather than the varargs method.
78 *
79 * @param columns list of BasicColumn
80 * @return an array of BasicColumn
81 */
82 static BasicColumn[] columnList(BasicColumn... columns) {
83 return columns;
84 }
85 }