SQL Server Date Range Comparisons: BETWEEN vs. =?

Comparing Date Ranges in SQL Server: BETWEEN vs <= and >=

In SQL Server versions 2000 and 2005, the BETWEEN keyword provides a concise alternative to using the <= and >= operators for comparing date ranges. However, understanding the nuances of these syntaxes is crucial for effective data selection.

Difference Between BETWEEN and <= and >=

BETWEEN is a shortcut that is equivalent to the following longer syntax:

EventDate >= '10/15/2009' AND EventDate <= '10/18/2009'

Both syntaxes return the same result: all rows where the EventDate column falls within the specified range.

When to Use Each Syntax

Use the BETWEEN keyword when you want to specify an inclusive range, where both endpoints are included. This is the most common scenario.

Use the longer syntax when you need to exclude one or both endpoints. For example:

EventDate >= '10/15/2009' AND EventDate < '10/19/2009'

This query excludes rows where the EventDate is equal to '10/19/2009'.

Dealing with DATETIME Data Type

When comparing DATETIME values, it's important to consider the time component as well. By default, BETWEEN and <= and >= compare only the date portion.

To include the time portion in the comparison, specify the full value, including the time down to the second:

EventDate BETWEEN '2009-10-15 00:00' AND '2009-10-18 23:59:59'

This query will correctly include all rows for the given date range, including the time component.

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