日期转换不适用于样式103

Question

I have saved my date as a nvarchar(50) datatype in SQL Server. When I run this query:

select [Client_code], Date_of_receipt 
from [T_Receving] 

I am getting output like this:

but I want to filter my records by particular date, so I wrote a query like this

select 
    convert(date, [Date_of_receipt], 103) as 'Date_of_Receipt' 
from  
    [T_Receving]  
where  
    convert(date, [Date_of_receipt], 103) between '2015-03-06' and '2018-05-06'    

but its showing an error

Conversion failed when converting date and/or time from character string

Answer 1

You clearly have some bad data. Use try_convert() :

select try_convert(DATE, Date_of_receipt, 103) as Date_of_Receipt 
from T_Receving
where try_convert(DATE, Date_of_receipt, 103) between '2015-03-06' and '2018-05-06'  ;

In SQL Server 2008, you have to work harder to find the culprits. You can start with:

select date_of_receipt
from T_Receving
where date_of_receipt not like '[0-3][0-9]/[0-1][0-9]/[0-9][0-9][0-9][0-9]'

This will find most instances of bad formats. If it still persists, you will have to dig deeper to find bad day or month numbers.

Answer 2

You have to convert to datetime and then convert back to varchar

 declare @dtv varchar(20) = '2018-17-04'
 declare @dtvdt datetime = convert(datetime, @dtv, 103) 
 select  @dtvdt;
 select convert(varchar(20), convert(datetime, @dtv, 103), 103), @dtv
 where  convert(datetime, @dtv, 103) between '2015-03-06' and '2018-05-06'