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!

--
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http://www.dbmonster.com/Uwe/Forums...eneral/200611/1

Lew

Guest

n/a Posts

March 9th, 2007
01:35 PM
#2

Re: If criteria is Null then show all.

valntyn via DBMonster.com wrote:

Quote:

Originally Posted by

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.

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

Lew

Guest

n/a Posts

March 9th, 2007
01:35 PM
#3

Re: If criteria is Null then show all.

Lew wrote:

Quote:

Originally Posted by

valntyn via DBMonster.com wrote:

Quote:

Originally Posted by

>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.

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

HansH

Guest

n/a Posts

March 9th, 2007
03:35 PM
#4

Re: If criteria is Null then show all.

"valntyn via DBMonster.com" <u29706@uweschreef in bericht
news:6ed7203954842@uwe...

Quote:

Originally Posted by

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.
>

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