我使用下面的代码来检查临时表是否存在,如果它存在,则在重新创建之前删除表。只要我不改变列,它就可以工作。如果我稍后添加一个列,它会给出一个错误,说“无效列”。请让我知道我做错了什么。
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
DROP TABLE #Results
CREATE TABLE #Results
(
Company CHAR(3),
StepId TINYINT,
FieldId TINYINT,
)
select company, stepid, fieldid from #Results
--Works fine to this point
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
DROP TABLE #Results
CREATE TABLE #Results
(
Company CHAR(3),
StepId TINYINT,
FieldId TINYINT,
NewColumn NVARCHAR(50)
)
select company, stepid, fieldid, NewColumn from #Results
--Does not work
我认为问题是你需要在两者之间添加GO语句,将执行分开成批。作为第二个删除脚本,即IF OBJECT_ID('tempdb..#Results') IS NOT NULL drop TABLE #Results没有删除临时表作为单个批处理的一部分。你可以试试下面的脚本吗?
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
DROP TABLE #Results
CREATE TABLE #Results
(
Company CHAR(3),
StepId TINYINT,
FieldId TINYINT,
)
GO
select company, stepid, fieldid from #Results
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
DROP TABLE #Results
CREATE TABLE #Results
(
Company CHAR(3),
StepId TINYINT,
FieldId TINYINT,
NewColumn NVARCHAR(50)
)
GO
select company, stepid, fieldid, NewColumn from #Results
我无法重现这个错误。
也许我没有理解这个问题。
下面的工作为我在SQL Server 2005,与额外的“foo”列出现在第二个选择结果:
IF OBJECT_ID('tempdb..#Results') IS NOT NULL DROP TABLE #Results
GO
CREATE TABLE #Results ( Company CHAR(3), StepId TINYINT, FieldId TINYINT )
GO
select company, stepid, fieldid from #Results
GO
ALTER TABLE #Results ADD foo VARCHAR(50) NULL
GO
select company, stepid, fieldid, foo from #Results
GO
IF OBJECT_ID('tempdb..#Results') IS NOT NULL DROP TABLE #Results
GO