Wrapper设置setSelect需要注意的一点

因为我的项目里边已经设置返回Map的时候,将Map内的Key转换为驼峰的命名表达式，但是使用BaseMapper时，发现接口传递过来的却是全部小写不符合驼峰的写法，然后我就去对比代码，发现造成这样的结果是因为EntityWrapper没有设置sqlSelect

{
    "msg": "查询成功",
    "code": 0,
    "data": {
        "list": [
            {
                "fdaltertime": null,
                "fdalterid": null,
                "fdstatus": 1,
                "fdmaxusers": null,
                "fddiscountamount": 100,
                "fdcreateid": null,
                "fdname": "满50减10",
                "fdcreatetime": null,
                "fdhaveusers": null,
                "fdid": "1",
                "fdminamount": 10,
                "fddiscountration": null,
                "fdtype": 1,
                "fdstartdate": null,
                "fdenddate": null
            },
            {
                "fdaltertime": null,
                "fdalterid": null,
                "fdstatus": 1,
                "fdmaxusers": null,
                "fddiscountamount": null,
                "fdcreateid": null,
                "fdname": "满500打8折",
                "fdcreatetime": null,
                "fdhaveusers": null,
                "fdid": "2",
                "fdminamount": 10,
                "fddiscountration": 20,
                "fdtype": 2,
                "fdstartdate": null,
                "fdenddate": null
            }
        ]
    }
}

 

	public Map query(Map params) {
		int status = Integer.parseInt(String.valueOf(params.get("fdStatus")));
		String studentId = String.valueOf(params.get("fdStudentId"));
		EntityWrapper wrapper = new EntityWrapper();
		if (2==status) {//已使用
			List list = couponDao.getCouponIdListByStudentId(studentId);
			wrapper.in("FD_ID", list);
		}else {
			wrapper.eq("FD_STATUS", status);
		}
		Map map = new HashMap();
		map.put("list", couponDao.selectMaps(wrapper));
		return map;
	}

 后台打印的sql

设置 了sqlSelect

public Map query(Map params) {
		int status = Integer.parseInt(String.valueOf(params.get("fdStatus")));
		String studentId = String.valueOf(params.get("fdStudentId"));
		EntityWrapper wrapper = new EntityWrapper();
		if (2==status) {//已使用
			List list = couponDao.getCouponIdListByStudentId(studentId);
			wrapper.in("FD_ID", list);
		}else {
			wrapper.eq("FD_STATUS", status);
		}
		wrapper.setSqlSelect("FD_ID,FD_NAME,FD_END_DATE,FD_TYPE,FD_MIN_AMOUNT,FD_DISCOUNT_AMOUNT,FD_DISCOUNT_RATION");
		Map map = new HashMap();
		map.put("list", couponDao.selectMaps(wrapper));
		return map;
	}

接口结果

{
    "msg": "查询成功",
    "code": 0,
    "data": {
        "list": [
            {
                "fdMinAmount": 10,
                "fdEndDate": null,
                "fdDiscountRation": null,
                "fdId": "1",
                "fdDiscountAmount": 100,
                "fdName": "满50减10",
                "fdType": 1
            },
            {
                "fdMinAmount": 10,
                "fdEndDate": null,
                "fdDiscountRation": 20,
                "fdId": "2",
                "fdDiscountAmount": null,
                "fdName": "满500打8折",
                "fdType": 2
            }
        ]
    }
}

 追本溯源

发现Wrapper.class的源代码

 /**
     * 

     * 使用字符串数组封装sqlSelect，便于在不需要指定 AS 的情况下通过实体类自动生成的列静态字段快速组装 sqlSelect，

     * 减少手动录入的错误率
     * 
     * @param columns 字段
     * @return
     */
    public Wrapper setSqlSelect(String... columns) {
        StringBuilder builder = new StringBuilder();
        for (String column : columns) {
            if (StringUtils.isNotEmpty(column)) {
                if (builder.length() > 0) {
                    builder.append(",");
                }
                builder.append(column);
            }
        }
        this.sqlSelect = builder.toString();
        return this;
    }

    /**
     * 

     * 使用对象封装的setsqlselect
     * 
     *
     * @param column 字段
     * @return
     */
    public Wrapper setSqlSelect(Column... column) {
        if (ArrayUtils.isNotEmpty(column)) {
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < column.length; i++) {
                if (column[i] != null) {
                    String col = column[i].getColumn();
                    String as = column[i].getAs();
                    if (StringUtils.isEmpty(col)) {
                        continue;
                    }
                    builder.append(col).append(as);
                    if (i < column.length - 1) {
                        builder.append(",");
                    }
                }
            }
            this.sqlSelect = builder.toString();
        }
        return this;
    }

    /**
     * 

     * 使用对象封装的setsqlselect
     * 
     *
     * @param columns 字段
     * @return
     */
    public Wrapper setSqlSelect(Columns columns) {
        Column[] columnArray = columns.getColumns();
        if (ArrayUtils.isNotEmpty(columnArray)) {
            setSqlSelect(columnArray);
        }
        return this;
    }

当没有指定sqlSelect时，会去调用Column.class的getAs()方法

public String getAs() {
        if (StringUtils.isEmpty(getColumn()) || StringUtils.isEmpty(as)) {
            return StringUtils.EMPTY;
        }
        String quote = null;
        if (isEscape() && SqlRunner.FACTORY != null) {
            GlobalConfiguration globalConfig = GlobalConfigUtils.getGlobalConfig(SqlRunner.FACTORY.getConfiguration());
            quote = globalConfig.getIdentifierQuote() == null ? globalConfig.getDbType().getQuote() : globalConfig.getIdentifierQuote();
        }
        return AS + (StringUtils.isNotEmpty(quote) ? String.format(quote, as) : as);
}