从字符串整数数据类型中获取MySQL数据

Question

我想从日期和日期获得总和（成本）的数据。我的表字段数据类型是id是INT AUTO INCREMENT，dd是varchar，mm是varchar，yyyy varchar和dd值是01到31，mm值是01到12，年值是4位数年份（2016或2015 ... ） 我想要总和（成本）= 143

SELECT SUM(cost) FROM costing
WHERE 
    (( dd> CAST('05' AS SIGNED) AND mm= CAST('12' AS SIGNED) AND yyyy= CAST('2015' AS SIGNED))
  AND
    ((dd<= CAST('23' AS SIGNED) AND mm = CAST('01' AS SIGNED) AND yyyy= CAST('2016' AS SIGNED)))

  order by id

Answer 1

您可以像这样使用CAST AS DATE函数：

SELECT 
     SUM(cost) FROM costing
WHERE
     CAST(CONCAT(yyyy,mm,dd) AS DATE) BETWEEN '2015-12-05' AND '2016-01-23'

Answer 2

首先，您应该考虑您的数据类型。日期不应该在varchar或整数数据类型中。请参阅此http://www.w3schools.com/sql/sql_datatypes.asp

然后你可以在之间使用。请参阅此http://www.w3schools.com/sql/sql_between.asp

然后您的查询中不需要order by id。

您的查询会喜欢 SELECT SUM(cost) FROM costing WHERE costingdate BETWEEN "5-12-2015" AND 23-1-2015"