mapper接口如下：

int updateGoodsStockNum(@Param("stockDTOS") List<GoodsStockDTO> stockDTOS);

在xml配置如下：

<update id="updateGoodsStockNum">

        <foreach collection="stockDTOS" item="goodsItem">

            update tb_newbee_mall_goods_info set stock_num = stock_num-#{goodsItem.goodsCount}

            where goods_id = #{goodsItem.goodsId} and stock_num>=#{goodsItem.goodsCount} and goods_sell_status = 0;

        </foreach>

    </update>

在执行一条记录没报错，只有在多条情况下就会如下错误

2022-06-15 10:10:44.215 DEBUG 5756 -- [nio-5180-exec-8] o.s.jdbc.support.SQLErrorCodesFactory : Caching SQL error codes for DataSource [com.king.framework.datasource.DynamicDataSource@4749770c]: database product name is 'MySQL'

2022-06-15 10:10:44.215 DEBUG 5756 -- [nio-5180-exec-8] s.j.s.SQLErrorCodeSQLExceptionTranslator : Translating SQLException with SQL state '42000', error code '1064', message [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'update bg_goods set stock_num = stock_num-2

            where goods_id = 10003 a' at line 4] for task [

### Error updating database. Cause: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'update bg_goods set stock_num = stock_num-2

            where goods_id = 10003 a' at line 4

### The error may exist in file [H:\workspace\java\king5180it\target\classes\mybatis\product\GoodsMapper.xml]

### The error may involve defaultParameterMap

### The error occurred while setting parameters

### SQL: update bg_goods set stock_num = stock_num-? where goods_id = ? and stock_num>=? and goods_sell_status = 0; update bg_goods set stock_num = stock_num-? where goods_id = ? and stock_num>=? and goods_sell_status = 0;

### Cause: java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'update bg_goods set stock_num = stock_num-2

            where goods_id = 10003 a' at line 4

起初以为是sql拼写问题，但多次检查确定是没问题，最后找到解决方法

数据连接需要加一个允许批量执行的配置

allowMultiQueries=true

最后记录下来，供大家学习分享。