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Mybatis-plus自定义SQL注入器查询@TableLogic逻辑删除后的数据详解

2023-03-09 17:45

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1 需求

Mybatis-plus使用@TableLogic注解进行逻辑删除数据后，在某些场景下，又需要查询该数据时，又不想写SQL。

2 解决方案

自定义Mybatis-plus的SQL注入器一劳永逸的解决该问题

3 方案：

3.1 方案1，继承 AbstractMethod拼接SQL语句

public class SelectIgnoreLogicDeleteByMap extends AbstractMethod {
 
    @Override
    public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
 
        String sqlBase= "<script>SELECT %s FROM %s %s\n</script>";
        String sqlScript = this.sqlWhereByMap(tableInfo);
        String sql = String.format(sqlBase, this.sqlSelectColumns(tableInfo, false), tableInfo.getTableName(), sqlScript);
        SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, Map.class);
        return this.addSelectMappedStatementForTable(mapperClass, "selectIgnoreLogicDeleteByMap", sqlSource, tableInfo);
    }
 
    
    protected String sqlWhereByMap(TableInfo table) {
        String sqlScript;
        sqlScript = SqlScriptUtils.convertChoose("v == null", " ${k} IS NULL ", " ${k} = #{v} ");
        sqlScript = SqlScriptUtils.convertForeach(sqlScript, "cm", "k", "v", "AND");
        sqlScript = SqlScriptUtils.convertWhere(sqlScript);
        sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("%s != null and !%s", "cm", "cm.isEmpty"), true);
        return sqlScript;
    }
}

3.2. 方案2，继承 AbstractMethod拼接SQL语句

public class SelectIgnoreLogicDelete extends AbstractMethod {
 
    @Override
    public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
 
        String sqlBase = "<script>%s SELECT %s FROM %s %s %s %s\n</script>";
 
        String sql = String.format(sqlBase, this.sqlFirst(), this.sqlSelectColumns(tableInfo, true), tableInfo.getTableName(), this.sqlWhereEntityWrapper(true, tableInfo), this.sqlOrderBy(tableInfo), this.sqlComment());
        SqlSource sqlSource = this.languageDriver.createSqlSource(this.configuration, sql, modelClass);
        return this.addSelectMappedStatementForTable(mapperClass, "selectIgnoreLogicDelete", sqlSource, tableInfo);
    }
 
    
    protected String sqlWhereEntityWrapper(boolean newLine, TableInfo table) {
        String sqlScript = table.getAllSqlWhere(false, true, "ew.entity.");
        sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", "ew.entity"), true);
        sqlScript = sqlScript + "\n";
        sqlScript = sqlScript + SqlScriptUtils.convertIf(String.format(SqlScriptUtils.convertIf(" AND", String.format("%s and %s", "ew.nonEmptyOfEntity", "ew.nonEmptyOfNormal"), false) + " ${%s}", "ew.sqlSegment"), String.format("%s != null and %s != '' and %s", "ew.sqlSegment", "ew.sqlSegment", "ew.nonEmptyOfWhere"), true);
        sqlScript = SqlScriptUtils.convertWhere(sqlScript) + "\n";
        sqlScript = sqlScript + SqlScriptUtils.convertIf(String.format(" ${%s}", "ew.sqlSegment"), String.format("%s != null and %s != '' and %s", "ew.sqlSegment", "ew.sqlSegment", "ew.emptyOfWhere"), true);
        sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", "ew"), true);
        return newLine ? "\n" + sqlScript : sqlScript;
    }

4. 自定义SQL注入器，注册上述自定义的方法

public class CustomSqlInjector extends DefaultSqlInjector {
 
    @Override
    public List<AbstractMethod> getMethodList(Class<?> mapperClass, TableInfo tableInfo) {
        List<AbstractMethod> methodList = super.getMethodList(mapperClass, tableInfo);
        methodList.add(new SelectIgnoreLogicDeleteByMap());
        methodList.add(new SelectIgnoreLogicDelete());
        return methodList;
    }
}

5. 自定义基础mapper，声明注册的方法

public interface CustomBaseMapper<T> extends BaseMapper<T> {
 
    
    List<T> selectIgnoreLogicDeleteByMap(@Param("cm") Map<String, Object> columnMap);
 
    
    List<T> selectIgnoreLogicDelete(@Param("ew") Wrapper<T> queryWrapper);
}

6. 使用声明的方法

6.1 业务mapper继承自定义的CustomBaseMapper

@Mapper
public interface UserMapper extends CustomBaseMapper<User> {
}

6.2 调用方法selectIgnoreLogicDelete

    @Override
    public List<User> getIgnoreDeleteById(Long userId) {
        LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(User::getId,userId);
        return this.baseMapper.selectIgnoreLogicDelete(queryWrapper);
    }

6.3 调用方法selectIgnoreLogicDeleteByMap

    @Override
    public List<User> getIgnoreDeleteById(Long userId) {
		Map<String, Object> columnMap = new HashMap<>(2);
        columnMap.put("id", userId);
        return this.baseMapper.selectIgnoreLogicDeleteByMap(columnMap);
    }