If criteria is Null then show all.

I have an .asp page that passes four variables to another .asp page by using
an HTML form. A SQL query then runs against an Access database using those
four variables. The variables are: "cnty", "rte", "bgn", and "nd".

My current SQL statement is as follows:

SQL = "SELECT * FROM Construction WHERE County='" & cnty & "' AND Route='" &
rte & "' AND Begin<=" & nd & " AND Ending>=" & bgn & ""

This works just fine, but I would like to add the ability to make "nd" and
"bgn" Null (leave those fields blank on the HTML form), and then return all
records that match the "cnty" and "rte" variables. I have an SQL Query in
the Access database that does this perfectly but I'm having trouble getting
the same functionality on the web.

Any help is greatly appreciated!

--
Message posted via DBMonster.com
http://www.dbmonster.com/Uwe/Forums....neral/200611/1

re: If criteria is Null then show all.

valntyn via DBMonster.com wrote:Pseudocode:

if ( empty( cnty ))
SQL = "SELECT * FROM Construction WHERE Route='" & rte & "' AND Begin<=" &
nd & " AND Ending>=" & bgn

else
SQL = "SELECT * FROM Construction WHERE County='" & cnty & "' AND Route='"
& rte & "' AND Begin<=" & nd & " AND Ending>=" & bgn

-- Lew

re: If criteria is Null then show all.

Lew wrote:Sorry, I focused on the wrong variable:

Pseudocode:

if ( empty( bgn ) OR empty( nd ) )
SQL = "SELECT * FROM Construction WHERE County='" & cnty & "' AND
Route='" & rte & "' "

else
SQL = "SELECT * FROM Construction WHERE County='" & cnty & "' AND
Route='" & rte & "' AND Begin<=" & nd & " AND Ending>=" & bgn

-- Lew

re: If criteria is Null then show all.

"valntyn via DBMonster.com" <u29706@uweschreef in bericht
news:6ed7203954842@uwe...How about ...
FLAG = empty( bgn ) OR empty( nd ) ? 'true' : 'false';
SQL = "SELECT * FROM Construction WHERE County='" & cnty
& "' AND Route='" & rte
& "' AND ( " & FLAG
& " or Begin<=0" & nd & " AND Ending>=0" & bgn & " )"

Note: assuming numerical input for nd and bgn, thus prepending 0.

Leaving out vowels in variable names ... Hebrew background?

HansH