Question

SELECT SUM(IF(create_month = MONTH(NOW() - INTERVAL 1 MONTH)
          AND create_year = YEAR(NOW() - INTERVAL 1 MONTH), 1, 0)) AS lastmonth,
   SUM(IF(create_month = MONTH(NOW() - INTERVAL 2 MONTH)
          AND create_year = YEAR(NOW() - INTERVAL 2 MONTH), 1, 0)) AS lastmonth2
FROM incident_view
WHERE customer_company_name = "Company"

大家好，

如何将两个结果（lastmonth和lastmonth2，它们都是Int）转换为Bigdecimal类型/ double或任何其他十进制类型？

会感激一些帮助。

干杯

Answer 1

您提到BigDecimal，这是一种Java类型，而不是MySQL类型。在任何情况下，documentation建议使用多种类型（包括NUMERIC或DECIMAL MySQL类型）与Java BigDecimal进行转换，因此，演员可能看起来像这样：

SELECT CAST(SUM(IF(create_month = MONTH(NOW() - INTERVAL 1 MONTH)
         AND create_year = YEAR(NOW() - INTERVAL 1 MONTH), 1, 0)) AS NUMERIC) AS lastmonth,
       CAST(SUM(IF(create_month = MONTH(NOW() - INTERVAL 2 MONTH)
         AND create_year = YEAR(NOW() - INTERVAL 2 MONTH), 1, 0)) AS NUMERIC) AS lastmonth2
FROM incident_view
WHERE customer_company_name = "Company"

Answer 2

使用CAST( .. AS DECIMAL)

SELECT 
    CAST(SUM(IF(create_month = MONTH(NOW() - INTERVAL 1 MONTH)
          AND create_year = YEAR(NOW() - INTERVAL 1 MONTH), 1, 0)) AS DECIMAL) AS lastmonth,
    CAST(SUM(IF(create_month = MONTH(NOW() - INTERVAL 2 MONTH)
          AND create_year = YEAR(NOW() - INTERVAL 2 MONTH), 1, 0)) AS DECIMAL) AS lastmonth2
FROM incident_view
WHERE customer_company_name = "Company"

SQL - 在BigDecimal中

2 个答案: