Stripping date from string, casting to date and checking if equal to today's date - sql

Question

I have a character field representing a date in the following format:
'yyyyMMdd-000000'
I'm not completely sure what the 0's represent, but I'm trying to strip those off then check if the date is the same as today's date:
SELECT
acctnum,
acctname
FROM
[Server].[dbo].[Table1]
Where
CAST(LEFT(myDate,8) AS DATE) = CAST(GetDate() as Date)
When executing that statement I get this error:
Conversion failed when converting date and/or time from character string.
What am I doing wrong and how could I fix this?

Answer 1

Use try_cast() instead:
Where TRY_CAST(LEFT(myDate, 8) AS DATE) = CAST(GetDate() as Date)
Then, you can find the bad data using:
select myDate
from [Server].[dbo].[Table1]
Where TRY_CAST(LEFT(myDate, 8) AS DATE) is null;
You can attempt to find the bad data with something like:
select myDate
from [Server].[dbo].[Table1]
where mydate not like '[12][90][0-9][01][0-9][0-9][1-3][0-9]%'
This doesn't find all bad examples, but if something is glaring it will pop.

Answer 2

declare #table1 table
(
acctnum int,
acctname varchar(10),
myDate varchar(20)
)
insert into #table1(acctnum, acctname, myDate)
values(1, 'A', '20200401-000000'),
(2, 'B', convert(varchar(20), getdate(), 112) + '-000000'),
(3, 'C', convert(varchar(20), getdate(), 112) + '-000000'),
(4, 'D', 'abcd-0000');
select *
from #table1;
select *, case isdate(stuffdate) when 1 then cast(stuffdate as date) end
from
(
select *, stuff(stuff(stuff(myDate, 14, 0, ':'), 12, 0, ':'), 9, 1, ' ') as stuffdate
from #table1
where myDate like convert(varchar(20), getdate(), 112)+'%'
) as t;
select *
from
(
select *, stuff(stuff(stuff(myDate, 14, 0, ':'), 12, 0, ':'), 9, 1, ' ') as stuffdate
from #table1
) as t
where case isdate(stuffdate) when 1 then cast(stuffdate as date) end = convert(varchar(20), getdate(), 112);