001/*
002 *  Copyright (c) 2022-2025, Mybatis-Flex (fuhai999@gmail.com).
003 *  <p>
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *  <p>
008 *  http://www.apache.org/licenses/LICENSE-2.0
009 *  <p>
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016
017package com.mybatisflex.core.activerecord.query;
018
019import com.mybatisflex.core.activerecord.Model;
020import com.mybatisflex.core.query.RelationsBuilder;
021import com.mybatisflex.core.util.LambdaGetter;
022
023import java.io.Serializable;
024
025/**
026 * 使用 {@code Relations Query} 的方式进行关联查询。
027 *
028 * @author 王帅
029 * @since 2023-07-30
030 */
031public class RelationsQuery<T extends Model<T>> extends RelationsBuilder<T> {
032
033    public RelationsQuery(Model<T> model) {
034        super(model);
035    }
036
037    @Override
038    public RelationsQuery<T> ignoreRelations(String... fields) {
039        super.ignoreRelations(fields);
040        return this;
041    }
042
043    @Override
044    public <L> RelationsQuery<T> ignoreRelations(LambdaGetter<L>... fields) {
045        super.ignoreRelations(fields);
046        return this;
047    }
048
049    @Override
050    public RelationsQuery<T> maxDepth(int maxDepth) {
051        super.maxDepth(maxDepth);
052        return this;
053    }
054
055    @Override
056    public RelationsQuery<T> extraConditionParam(String key, Object value) {
057        super.extraConditionParam(key, value);
058        return this;
059    }
060
061    protected Object pkValue() {
062        // 懒加载，实际用到的时候才会生成 主键值
063        return ((Model<T>) delegate).pkValue();
064    }
065
066    /**
067     * 根据主键查询一条数据。
068     *
069     * @return 一条数据
070     */
071    public T oneById() {
072        return baseMapper().selectOneWithRelationsById((Serializable) pkValue());
073    }
074
075    /**
076     * 根据主键查询一条数据，返回的数据为 asType 类型。
077     *
078     * @param asType 接收数据类型
079     * @param <R>    接收数据类型
080     * @return 一条数据
081     */
082    public <R> R oneByIdAs(Class<R> asType) {
083        return baseMapper().selectOneWithRelationsByIdAs((Serializable) pkValue(), asType);
084    }
085
086}