tk.mybatis 通用批量更新接口设计（方法一：通过foreach批量更新）

通过foreach批量更新

1、pom

        <!-- tk.mybatis -->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>

2、注解接口 -> MyInsertListSelectiveMapper.java

package com.sundear.base.mybatis.tk.base;

import com.sundear.base.mybatis.tk.provider.MyUpdateListForeachProvider;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.UpdateProvider;
import tk.mybatis.mapper.annotation.RegisterMapper;

import java.util.List;

/**
 * @Author: 秀丽
 * @Date: 2021/5/25 17:43
 * @description 自定义，根据id批量修改 foreach 效率其实很可观
 */
@RegisterMapper
public interface MyUpdateListForeachMapper<T> {

    /**
     * 自定义，根据id批量修改 foreach 效率其实很可观.
     * 注意：
     * 1、该方法返回不了被修改成功的条数：0-》全部未修改成功 1—》全部修改成功or部分修改成功
     * 2、使用这个方法需要关闭防火墙（若有）-》spring.datasource.druid.filters中不能又wall参数
     * 3、sql url中需要有     &allowMultiQueries=true     参数
     *
     * @param var1
     * @return 0-》全部未修改成功 1—》全部修改成功or部分修改成功
     */
    @UpdateProvider(
            type = MyUpdateListForeachProvider.class,
            method = "dynamicSQL"
    )
    int myUpdateListForeachByPrimaryKey(@Param("records") List<T> var1);
}

3、MyUpdateListForeachProvider.java

package com.sundear.base.mybatis.tk.provider;

import org.apache.ibatis.mapping.MappedStatement;
import tk.mybatis.mapper.annotation.Version;
import tk.mybatis.mapper.entity.EntityColumn;
import tk.mybatis.mapper.mapperhelper.EntityHelper;
import tk.mybatis.mapper.mapperhelper.MapperHelper;
import tk.mybatis.mapper.mapperhelper.MapperTemplate;
import tk.mybatis.mapper.mapperhelper.SqlHelper;
import tk.mybatis.mapper.version.VersionException;

import java.util.Iterator;
import java.util.Set;

/**
 * @Author: 秀丽
 * @Date: 2021/5/25 17:43
 * @description 自定义，根据id批量修改 foreach 效率其实很可观
 */
public class MyUpdateListForeachProvider extends MapperTemplate {

    public MyUpdateListForeachProvider(Class<?> mapperClass, MapperHelper mapperHelper) {
        super(mapperClass, mapperHelper);
    }

    public String myUpdateListForeachByPrimaryKey(MappedStatement ms) {
        Class<?> entityClass = this.getEntityClass(ms);
        StringBuilder sql = new StringBuilder();
        sql.append("<bind name=\"listNotEmptyCheck\" value=\"@tk.mybatis.mapper.util.OGNL@notEmptyCollectionCheck(records, '" + ms.getId() + " 方法参数为空')\"/>");
        sql.append("<foreach collection=\"records\" item=\"record\" index=\"index\" open=\"\" close=\"\" separator=\";\">");
        sql.append(SqlHelper.updateTable(entityClass, this.tableName(entityClass)));
        sql.append(SqlHelper.updateSetColumns(entityClass, "record", true, this.isNotEmpty()));
        sql.append(wherePKColumns(entityClass, "record", true));
        sql.append("</foreach>");
        return sql.toString();
    }

    /**
     * 需要重写SqlHelper中的方法，因为SqlHelper的useVersion在foreach中不能用。
     *
     * @param entityClass
     * @param entityName
     * @param useVersion
     * @return
     */
    private String wherePKColumns(Class<?> entityClass, String entityName, boolean useVersion) {
        StringBuilder sql = new StringBuilder();
        boolean hasLogicDelete = SqlHelper.hasLogicDeleteColumn(entityClass);
        sql.append("<where>");
        Set<EntityColumn> columnSet = EntityHelper.getPKColumns(entityClass);
        Iterator var6 = columnSet.iterator();

        while (var6.hasNext()) {
            EntityColumn column = (EntityColumn) var6.next();
            sql.append(" AND ").append(column.getColumnEqualsHolder(entityName));
        }

        if (useVersion) {
            sql.append(whereVersion(entityClass, entityName));
        }

        if (hasLogicDelete) {
            sql.append(SqlHelper.whereLogicDelete(entityClass, false));
        }

        sql.append("</where>");
        return sql.toString();
    }

    private String whereVersion(Class<?> entityClass, String entityName) {
        Set<EntityColumn> columnSet = EntityHelper.getColumns(entityClass);
        boolean hasVersion = false;
        String result = "";
        Iterator var4 = columnSet.iterator();

        while (var4.hasNext()) {
            EntityColumn column = (EntityColumn) var4.next();
            if (column.getEntityField().isAnnotationPresent(Version.class)) {
                if (hasVersion) {
                    throw new VersionException(entityClass.getCanonicalName() + " 中包含多个带有 @Version 注解的字段，一个类中只能存在一个带有 @Version 注解的字段!");
                }
                hasVersion = true;
                result = " AND " + column.getColumnEqualsHolder(entityName);
            }
        }

        return result;
    }
}

3、创建一个基础mapper继承我们自定义的接口 -》 MyBaseMapper.java

这个接口用以继承以后我们所写的所有tk自定义接口

package com.sundear.base.mybatis;

import com.sundear.base.mybatis.tk.base.MyUpdateListForeachMapper;

/**
 * @Author: 秀丽
 * @Date: 2021/5/8 17:41
 * @description 继承自定义的方法
 */
public interface MyBaseMapper<T> extends MyUpdateListForeachMapper<T>{

}

4、实体类mapper继承MyBaseMapper.java

package com.sundear.dao;

import com.sundear.pojo.TbTest;
import com.sundear.tk.MyBaseMapper;
import org.apache.ibatis.annotations.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;

/**
 * @Author: xiu
 * @Date: 2021/5/25 10:25
 * @description
 */
@Mapper
public interface TbTestMapper extends 
        tk.mybatis.mapper.common.Mapper<TbTest>, 
        MySqlMapper<TbTest>, 
        
        //这个就是我们自定义的通用mapper
        MyBaseMapper<TbTest> {

}

5、然后我们就可以用实体类的mapper直接调用  myUpdateListForeachByPrimaryKey(List<T> var1)  方法去批量更新了list了。