MybatisPlus of BaseMapper

I. Introduction 
　　In MybatisPlus in, BaseMapper defines some common CRUD methods, when our custom Mapper interface inheritance BaseMapper to have these methods. 

Two, BaseMapper method of CRUD

• General CRUD package BaseMapper interface to  Mybatis-Plus automatically resolve entity table mapping relationship start to convert  Mybatis internal object into the vessel
• Generics  T any solid object
• Parameters  Serializable for the primary key of any type  Mybatis-Plus is not recommended to use composite primary key conventions each table has its own unique  id primary key
• Object  Wrapper of  the condition constructor

/*
 * Copyright (c) 2011-2020, hubin ([email protected]).
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
packagecom.baomidou.mybatisplus.core.mapper; 

Import the java.io.Serializable;
 Import java.util.Collection;
 Import java.util.List;
 Import a java.util.Map; 

Import org.apache.ibatis.annotations.Param; 

Import com.baomidou.mybatisplus.core.conditions.Wrapper;
 Import com.baomidou.mybatisplus.core.metadata.IPage;
 Import com.baomidou.mybatisplus.core.toolkit.Constants;
 
/ ** 
 * <P> 
 * Mapper interface inheritance after, without writing mapper.xml file, you can get CRUD functionality 
 * </ the p-> 
 * <the p-> 
 * Mapper supports this generic id 
 * </ the p-> 
 * 
 * @author Hubin 
 *@Since 2016-01-23
  * / 
public  interface BaseMapper <T> { 

    / ** 
     * <P> 
     * insert a record 
     * </ P> 
     * 
     * @param Entity entity object
      * / 
    int INSERT (T Entity); 

    / * * 
     * <P> 
     * The delete ID 
     * </ P> 
     * 
     * @param ID primary key ID
      * / 
    int deleteById (the Serializable ID); 

    / ** 
     * <P> 
     * The columnMap condition, delete records 
     * </ P> 
     * 
     * @param columnMap table field map objects
     * / 
    Int deleteByMap (@Param (Constants.COLUMN_MAP) the Map <String, Object> columnMap); 

    / ** 
     * <P> 
     * The conditions entity, delete records 
     * </ P> 
     * 
     * @param queryWrapper packaging operations entity object class (can be null)
      * / 
    int delete (@Param (Constants.WRAPPER) the Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * delete (ID The mass delete) 
     * </ P> 
     * 
     * @param IDLIST primary key ID list (can not be null and empty)
      * / 
    int deleteBatchIds (@Param (Constants.COLLECTION) Collection <? the extends Serializable> IDLIST); 

    / **
     * <P> 
     * The modified ID 
     * </ P> 
     * 
     * @param Entity entity object
      * / 
    int updateById (@Param (Constants.ENTITY) T Entity); 

    / ** 
     * <P> 
     * The whereEntity condition update records 
     * </ P> 
     * 
     * @param entity entity object (set condition value is not null) 
     * @param updateWrapper packaging operations entity object class (can be null, which is used to generate the entity where clause)
      * / 
    int Update (@ param (Constants.ENTITY) T Entity, @Param (Constants.WRAPPER) the Wrapper <T> updateWrapper); 

    / ** 
     * <P> 
     * The ID inquiry 
     * </ p>
     * 
     *@param ID primary key ID
      * / 
    T selectById (the Serializable ID); 

    / ** 
     * <P> 
     * query (query based bulk ID) 
     * </ P> 
     * 
     * @param IDLIST primary key ID list (and can not be null empty)
      * / 
    List <T> selectBatchIds (@Param (Constants.COLLECTION) Collection <? the extends Serializable> IDLIST); 

    / ** 
     * <the p-> 
     * query (according to columnMap conditions) 
     * </ the p-> 
     * 
     * @param columnMap field map Object
      * / 
    List <T> selectByMap (@Param (Constants.COLUMN_MAP) the Map <String, Object>/**columnMap);

    
     * <P> 
     * The conditions entity, select a row 
     * </ P> 
     * 
     * @param queryWrapper entity object
      * / 
    T between selectOne (@Param (Constants.WRAPPER) the Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * The Wrapper conditions, the total number of records query 
     * </ P> 
     * 
     * @param queryWrapper entity object
      * / 
    Integer SelectCount (@Param (Constants.WRAPPER) Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * The entity conditions, query all the records 
     * </ p>
     * 
     * @Param queryWrapper packaging operations entity object class (which can be null)
     * / 
    List <T> selectList is (@Param (Constants.WRAPPER) Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * The Wrapper conditions, query all records 
     * </ P> 
     * 
     * @param queryWrapper entity object wrapper operation class (can be null)
      * / 
    List <the Map <String, Object >> selectMaps (@Param (Constants.WRAPPER) Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * The Wrapper conditions, query all records 
     * Note: returns the value of only the first field 
     * </ P> 
     * 
     * @param queryWrapper packaging operations entity object class (can be null)
      * / 
    List<Object> selectObjs (@Param (Constants.WRAPPER) the Wrapper <T> queryWrapper); 

    / ** 
     * <P> 
     * The entity conditions, all of the query record (and page) 
     * </ P> 
     * 
     * @param Page tab query (may RowBounds.DEFAULT) 
     * @param queryWrapper packaging operations entity object class (can be null)
      * / 
    the IPage <T> SelectPage (the IPage <T> Page, @Param (Constants.WRAPPER) the Wrapper <T> queryWrapper) ; 

    / ** 
     * <P> 
     * The Wrapper conditions, all of the query record (and page) 
     * </ P>
     * 
     * @Param Page tab query 
     * @param queryWrapper packaging operations entity object class
      * / 
    IPage <the Map <String, Object >> selectMapsPage (IPage <T> page, @Param (Constants.WRAPPER) Wrapper<T> queryWrapper);
}

Three, MybatisPlus learning

　　MybatisPlus: https://mp.baomidou.com/guide/crud-interface.html#mapper-crud-%E6%8E%A5%E5%8F%A3