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SQL to select only certain times within a date range

SQL to select only certain times within a date range

By  Rudy Limeback, SQL Consultant, r937.com

SearchOracle.com

I have a field in my table which stores dates and times in datetime format. I want to get the data from 10 p.m. to 6 a.m. between 1st July and 31st July. What's the best way to get this data?

This is one of the few times where having separate DATE and TIME columns would be beneficial.

select columns
  from table
 where datecol between '2007-07-01' and '2007-07-31'
   and (
       timecol >= '22:00'
    or timecol <= '06:00'
       )

With a DATETIME column, however, it's a little trickier. We need to "extract" the time portion of the DATETIME values. The query would look something like this:

select columns
  from table
 where datetimecol >= '2007-07-01' 
   and datetimecol  < '2007-08-01'
   and (
       extract(hour from datetimecol) >= 22
    or extract(hour_minute from datetimecol) <= '06:00'
       )

Exact syntax will depend on which database system you're using. Notice how the range test for the dates uses an open-ended interval.