SQL编号通配符问题

Question

I'm trying to add a wildcard to my date select query so i only pull the day not time. Ie 2021-03-11 17:54:30.123. I thought a number could be substituted for a #.

select AID, LocalCoAltIn,LocalCoAltOut,EventTime
from EXCDS.dbo.WKS_LOG_VIEW
where EventTime like '2021-03-11 ##:##:##:###';

My query is returning no values even though they are in the table. Thanks.

Answer 1

No: Don't use strings! One method is to convert to a date:

select AID, LocalCoAltIn,LocalCoAltOut,EventTime
from EXCDS.dbo.WKS_LOG_VIEW
where convert(date, EventTime) = '2021-03-11';

Another method is to use a range:

where EventTime >= '2021-03-11' and
      EventTime < '2021-03-12'

Answer 2

The LIKE operator in most flavors of SQL only support _ and * wildcards (matching any one single, or multiple characters). Gordon has given you a better approach, but if you wanted to fix your current query on SQL Server you could try:

SELECT AID, LocalCoAltIn, LocalCoAltOut, EventTime
FROM EXCDS.dbo.WKS_LOG_VIEW
WHERE EventTime LIKE '2021-03-11 [0-9][0-9]:[0-9][0-9]:[0-9][0-9]:[0-9][0-9][0-9]';

SQL Server extended the LIKE operator to accept a few extra things, such as character classes. Here [0-9] inside LIKE would match any single digit.

Answer 3

Not sure that like operator would work for date as you want, but you still have few options. Use DATEPART function to retrieve year\month\etc and compare it with exact value that you need

select AID, LocalCoAltIn,LocalCoAltOut,EventTime from EXCDS.dbo.WKS_LOG_VIEW where DATEPART(year,EventTime) = 2021 AND DATEPART(month,EventTime) = 3 AND DATEPART(day,EventTime = 11);

Or use Gordon Linoff suggestion if you dont care about exact date part and only need to compare entire date without time