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.logicdelete;
018
019import com.mybatisflex.core.dialect.IDialect;
020import com.mybatisflex.core.query.*;
021import com.mybatisflex.core.table.TableInfo;
022
023/**
024 * 数据列默认值为 {@code null} 值的逻辑删除处理器。
025 *
026 * @author 王帅
027 * @since 2023-07-30
028 */
029public abstract class NullableColumnLogicDeleteProcessor extends AbstractLogicDeleteProcessor {
030
031    @Override
032    public String buildLogicNormalCondition(String logicColumn, TableInfo tableInfo, IDialect dialect) {
033        return dialect.wrap(logicColumn) + " IS NULL";
034    }
035
036    @Override
037    public void buildQueryCondition(QueryWrapper queryWrapper, TableInfo tableInfo, String joinTableAlias) {
038        QueryTable queryTable = new QueryTable(tableInfo.getSchema(), tableInfo.getTableName()).as(joinTableAlias);
039        QueryColumn queryColumn = new QueryColumn(queryTable, tableInfo.getLogicDeleteColumn());
040        queryWrapper.and(queryColumn.isNull());
041    }
042
043    /**
044     * 逻辑删除字段值为 {@code null} 表示数据未删除。
045     */
046    @Override
047    public Object getLogicNormalValue() {
048        return null;
049    }
050
051}