sql-server - SQL Server:将表达式转换为数据类型bigint的算术溢出错误

Question

这是我的查询顺序:

SELECT
      CASE
         WHEN ((BarCode IS NOT NULL) AND (ExternelBarCode IS NULL)) THEN BarCode
         WHEN ((BarCode IS NULL) AND (ExternelBarCode IS NOT NULL)) THEN CAST(ExternelBarCode AS bigint)
         ELSE ExternelBarCode -- When both exist
      END AS TicketBarCode
...

运行它时，我收到以下消息:

Arithmetic overflow error converting expression to data type bigint.

列 BarCode的类型为 bigint，列 ExternelBarCode的类型为 varchar(250)。

BarCode = 178625624324,
ExternelBarCode = 2015591149641227565492

我该如何解决这个问题？

Answer 1

2,015,591,149,641,227,565,492的值大于bigint 2 ^ 63-1(9,223,372,036,854,775,807)中允许的最大值，因此无法进行转换。

如果需要返回数字值，可以将其强制转换为decimal(38,0)

SELECT
      CASE
         WHEN ((BarCode IS NOT NULL) AND (ExternelBarCode IS NULL)) THEN CAST(BarCode as decimal(38,0))
         WHEN ((BarCode IS NULL) AND (ExternelBarCode IS NOT NULL)) THEN CAST(ExternelBarCode AS decimal(38,0))
         ELSE cast(ExternelBarCode as decimal(38,0)) -- When both exist
      END AS TicketBarCode