SQL-如何在哪里搜索但忽略前两个字符

Question

I need to perform a date search but the data is a String with the format

'dd/mm/yyyy'

I want to search only for 'mm/yyyy'

For example I want all records that have '07/2014' regardless of what day?

I'm sure its something simple just can't figure it out

EDIT : It looks like the format is MM/DD/YYY Looks like I got this sorted just used:

RIGHT(BookedDate,5) = '/2014'
AND LEFT (BookedDate,2) = '7/'

Thanks All :)

Answer 1

If your string is in the format of dd/mm/yyyy always, as in 01/09/2014 you could use right:

declare @val as varchar(10)
Set @val='1/2/2014'
RIGHT(@val,7)

if you are not sure of the format but know that there is a / you could search for it:

declare @val as varchar(10)
Set @val='1/2/2014'
select right(@val,len(@val)-patindex('%/%',@val))   

Answer 2

myfield like '%/07/2014'

Beware, since the wildcard (%) is put at the beginning of the query no indexes (if they exist) will be used. This will always be a full table scan.

Answer 3

If you store your date values in character based column, than jyparask's answer is good enough, but if you store it in date/time based column, then use date/time functions or intervals:

WHERE
  myDateColumn >= '01/07/2014'
  AND myDateColumn < '01/08/2014'

The above WHERE condition means: all values in July, 2014.

Answer 4

这将确保（因为它是一个字符串）如果该值比预期的长，则将始终删除前三个字符。

  SELECT RIGHT(field, LEN(field)-3) FROM database

Answer 5

This feels like a very bad idea. Most likely there is a ton of optimizations that could be done automatically for your queries by the database if you used Date instead of the String. This is certainly going to be some kind of bottleneck if your database grows, it would have to ask and parse every single row to find out if it matches your request.