mybatisplus更新字段为null怎么处理？

    /**
     * 主键
     */
    @TableId(type = IdType.ASSIGN_ID)
    @ApiModelProperty(value = "主键")
    private String id;

    /**
     * 企业号
     */
    @ApiModelProperty(value = "企业号")
    @TableField(updateStrategy = FieldStrategy.IGNORED)
    private String sysOrgCode;

加上

@TableField(updateStrategy = FieldStrategy.IGNORED)

注意：使用时该字段必须传值，否则会更新为空。

//1、更新BUS_BILL_INFO_CUST
        BusBillInfoCust upBbc = new BusBillInfoCust();
        upBbc.setId(id);
        upBbc.setSysOrgCode(null);
        int num = busBillInfoCustMapper.updateById(upBbc);
        if (num == 0) {
            throw new JeecgBootException("更新BUS_BILL_INFO_CUST失败，请联系管理员");
        }

执行的sql为

update
    bus_bill_info_cust
set
    sys_org_code =null
where
    id ='953ea093ca1546c69b60d3a094d7d338'