1 /* 2 * Copyright 2009-2023 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.apache.ibatis.annotations; 17 18 import java.lang.annotation.Documented; 19 import java.lang.annotation.ElementType; 20 import java.lang.annotation.Repeatable; 21 import java.lang.annotation.Retention; 22 import java.lang.annotation.RetentionPolicy; 23 import java.lang.annotation.Target; 24 25 /** 26 * The annotation that specify a method that provide an SQL for retrieving record(s). 27 * <p> 28 * <b>How to use:</b> 29 * 30 * <pre> 31 * public interface UserMapper { 32 * 33 * @SelectProvider(type = SqlProvider.class, method = "selectById") 34 * User selectById(int id); 35 * 36 * public static class SqlProvider { 37 * public static String selectById() { 38 * return "SELECT id, name FROM users WHERE id = #{id}"; 39 * } 40 * } 41 * 42 * } 43 * </pre> 44 * 45 * @author Clinton Begin 46 */ 47 @Documented 48 @Retention(RetentionPolicy.RUNTIME) 49 @Target(ElementType.METHOD) 50 @Repeatable(SelectProvider.List.class) 51 public @interface SelectProvider { 52 53 /** 54 * Specify a type that implements an SQL provider method. 55 * 56 * @return a type that implements an SQL provider method 57 * 58 * @since 3.5.2 59 * 60 * @see #type() 61 */ 62 Class<?> value() default void.class; 63 64 /** 65 * Specify a type that implements an SQL provider method. 66 * <p> 67 * This attribute is alias of {@link #value()}. 68 * 69 * @return a type that implements an SQL provider method 70 * 71 * @see #value() 72 */ 73 Class<?> type() default void.class; 74 75 // @formatter:off 76 /** 77 * Specify a method for providing an SQL. 78 * <p> 79 * Since 3.5.1, this attribute can omit. 80 * <p> 81 * If this attribute omit, the MyBatis will call a method that decide by following rules. 82 * 83 * <ul> 84 * <li> 85 * If class that specified the {@link #type()} attribute implements the 86 * {@link org.apache.ibatis.builder.annotation.ProviderMethodResolver}, 87 * the MyBatis use a method that returned by it. 88 * </li> 89 * <li> 90 * If cannot resolve a method by {@link org.apache.ibatis.builder.annotation.ProviderMethodResolver} 91 * (= not implement it or it was returned <code>null</code>, 92 * the MyBatis will search and use a fallback method that named <code>provideSql</code> from 93 * specified type. 94 * </li> 95 * </ul> 96 * 97 * @return a method name of method for providing an SQL 98 */ 99 // @formatter:on 100 String method() default ""; 101 102 /** 103 * @return A database id that correspond this provider 104 * 105 * @since 3.5.5 106 */ 107 String databaseId() default ""; 108 109 /** 110 * Returns whether this select affects DB data.<br> 111 * e.g. RETURNING of PostgreSQL or OUTPUT of MS SQL Server. 112 * 113 * @return {@code true} if this select affects DB data; {@code false} if otherwise 114 * 115 * @since 3.5.12 116 */ 117 boolean affectData() default false; 118 119 /** 120 * The container annotation for {@link SelectProvider}. 121 * 122 * @author Kazuki Shimizu 123 * 124 * @since 3.5.5 125 */ 126 @Documented 127 @Retention(RetentionPolicy.RUNTIME) 128 @Target(ElementType.METHOD) 129 @interface List { 130 SelectProvider[] value(); 131 } 132 133 }