如何将 nvarchar 转换为 int

Question

I need to get data according to nvarchar coloumn that holds numbers,I get this error: Conversion failed when converting the nvarchar value '362X' to data type int. I tried this:

select  modelcode from model 
where  cast(modelcode as int )> 10000 - ERROR
where  cast(modelcode as bigint )> 10000 - ERROR
where  pws_modelcode+0 > 10000 - ERROR
order by ModelCode asc

What am I missing ?

Answer 1

In SQL Server, you can use try_convert() or try_cast() :

where try_cast(modelcode as int) > 10000

In other databases, you can use a case perhaps with regular expressions:

where (case when modelcode ~ '^[0-9]+$' then cast(modelcode as int) end) > 10000

Answer 2

将除减号以外的所有非数字字符替换为 null，然后转换为 INT。

select  modelcode from model where  cast(REGEXP_REPLACE(modelcode,'^0-9-','') as int )> 10000