Question

The following is my SP:

Alter PROCEDURE GetList 
(

@FromDate date = null,
@ToDate date = null

)
AS

Select * FROM CallList c
Where c.CallDate > @FromDate and c.CallDate < @ToDate 

If there was no passed date filter, I want to get all the records.

How would I do it?

Answer 1

A couple of viable options:

You could set @FromDate and @ToDate to be equal to a very early or very late date respectively they’re NULL.

You could use sp_executesql and construct a dynamic query string w/ parameters as needed e.g.

DECLARE @Sql NVARCHAR(MAX) = 'SELECT * FROM CallList C WHERE 1 = 1 '

IF @FromDate IS NOT NULL
BEGIN
  SET @Sql += ' AND C.CallDate > @xFromDate'
END

IF @ToDate IS NOT NULL
BEGIN
  SET @Sql += ' AND C.CallDate < @xToDate'
END

EXEC sp_executesql @Sql, N'@xFromDate DATETIME, @xToDate DATETIME', @xFromDate = @FromDate, @xToDate = @ToDate

This latter approach performs better than using ORs all over the place, as queries that include ORs invariably end up getting optimized very badly – they might work well for a certain set of parameters but are generally not one-size-fits-all.