SQL中的数据转换或数据映射错误

Question

这是我尝试执行的WinSQL查询。

SELECT ezait6 AS "MO No",
       vhitno AS "Item No",
       vhrefd AS "Finish Date",
       vhmaqa AS "Manuf Qty",
       vhmaun AS "U/M"
FROM m3edbtest.mwohed,
     m3edbtest.cinacc
WHERE ezcono = 1
      AND vhcono = ezcono
      AND vhrefd >= '20170801'
      AND vhrefd <= '20170831'
      AND vhmfno = ezait6;

- 不同的数据类型

- vhmfno ==＆gt;整数

- ezait6 ==＆gt;的nchar（8）

运行查询后，出现以下错误：

-- Error : SQL0802 - Data conversion or data mapping error.

我怀疑它是由不同的数据类型组成的 我的一个表“ezait6”中有一个nvarchar列。 那么我应该如何将这些值转换为INT类型。

Answer 1

您可以先检查varchar字段的内容是否为数字，并仅查询这些内容：

SELECT ezait6 AS "MO No",
       vhitno AS "Item No",
       vhrefd AS "Finish Date",
       vhmaqa AS "Manuf Qty",
       vhmaun AS "U/M"
FROM m3edbtest.mwohed,
     m3edbtest.cinacc
WHERE IsNumeric(ezait6)=1
      AND ezcono = 1
      AND vhcono = ezcono
      AND vhrefd >= '20170801'
      AND vhrefd <= '20170831'
      AND vhmfno = CONVERT(INT,ezait6);