SQL LIKE Statement on a DateTime Type

问题

How do you perform a LIKE statement on a column of DateTime datatype in SQL Server?

If I run the following SQL it returns me all the dates with 2009 in.

SELECT * FROM MyTable where CheckDate LIKE '%2009%'

However, if I want all the Oct, Nov & Dec dates I'd expect to be able to do the following:

SELECT * FROM MyTable where CheckDate LIKE '%2009-1%'

But this returns me nothing!

I'm giving the user a filter option where they type in the date string and as they type I filter the data. So if they type '20', I'd like to return all the dates with '20' within the date (so this could be all 2012 dates or a date value like 06/20/1999)

Can anybody help?

I'm using SQL Server 2008.

Thanks in advance.

回答1:

You can use the DATEPART function to extract portions of dates. It should also make your queries more explicit about what you're seeking to achieve:

SELECT * FROM MyTable
where DATEPART(year,CheckDate)=2009 and
      DATEPART(month,CheckDate) between 10 and 12

(There are also specifically named functions, such as MONTH and YEAR, but I prefer DATEPART for consistency since it can access all components of a datetime)

You should try to avoid thinking of datetimes as having any kind of string format. Treating them as strings is one of the largest sources of errors we encounter.

回答2:

If you need to use Like operator (for some reason) you have to convert the DateTime column into a varchar.

SELECT * 
FROM MyTable 
WHERE CONVERT(VARCHAR, CheckDate, 120) LIKE '%2009-1%'

回答3:

You can use something like this:

SELECT * 
FROM MyTable 
WHERE CheckDate >= '2009-10-01' AND CheckDate < '2010-01-01';

来源：https://stackoverflow.com/questions/11985536/sql-like-statement-on-a-datetime-type

标签

sql

sql-server-2008

datetime