Ad:

PHP Discussion Thread
Unsolved
Views: 489

Dec 20th, 2008

accessing an empty querry result

Expand Post »

I wish to know if there is any way to refear to an empty querry result.

I want to implement a safety measure that prevents users from entering duplicate names in a DB. so I colect the value they enter in a textbox, then I create a querry wich checks the DB's name column for values that are identical to the user inputed value.

so basicly if no result is found it should continue to add the entry to the DB.

PHP Syntax (Toggle Plain Text)
$sql_name_Check="SELECT DISTINCT table.name
		        FROM table
			WHERE table.nume = '$name'";
 
	$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());
 
	IF ( ISNULL ($rez_name_Check) )
{
code for adding the new entry
}
$sql_name_Check="SELECT DISTINCT table.name
		        FROM table
			WHERE table.nume = '$name'";

	$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());

	IF ( ISNULL ($rez_name_Check) )
{
code for adding the new entry
}

SO is there any way to check if a querry result is NULL and if so to execute a series of instructions?

marcmm

Reputation Points: 10

Solved Threads: 0

Light Poster

Offline

42 posts
since Oct 2008

Permalink

Dec 20th, 2008

Re: accessing an empty querry result

You want to check user name exists or not i.e. avoid duplicate entry in database

PHP Syntax (Toggle Plain Text)
$sql_name_Check="SELECT  table.name
		        FROM table
			WHERE table.nume = '$name'";
$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());
 
$num=mysql_num_rows($rez_name_Check);
if($num>1)
{
echo "User name already exists ";
}
else
{
echo "User name is available";
//Here insert value of form in database
 
}
$sql_name_Check="SELECT  table.name
		        FROM table
			WHERE table.nume = '$name'";
$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());

$num=mysql_num_rows($rez_name_Check);
if($num>1)
{
echo "User name already exists ";
}
else
{
echo "User name is available";
//Here insert value of form in database

}

Last edited by Aamit; Dec 20th, 2008 at 9:37 am.

Aamit

Reputation Points: 3

Solved Threads: 15

Posting Whiz

Offline

341 posts
since Apr 2008

Permalink

Dec 21st, 2008

Re: accessing an empty querry result

Aamit,

If condition will be "if($num>0)"

manish.s

Reputation Points: 10

Solved Threads: 5

Light Poster

Offline

29 posts
since Dec 2008

Permalink

Dec 22nd, 2008

Re: accessing an empty querry result

PHP Syntax (Toggle Plain Text)
$sql_name_Check="SELECT  table.name
		        FROM table
			WHERE table.nume = '$name'";
$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());
 
$num=mysql_num_rows($rez_name_Check);
if($num>=1)
{
echo "User name already exists ";
}
else
{
echo "User name is available";
//Here insert value of form in database
 
}
$sql_name_Check="SELECT  table.name
		        FROM table
			WHERE table.nume = '$name'";
$rez_name_Check = mysql_query($sql_name_Check) OR DIE (mysql_error());

$num=mysql_num_rows($rez_name_Check);
if($num>=1)
{
echo "User name already exists ";
}
else
{
echo "User name is available";
//Here insert value of form in database

}

Last edited by Aamit; Dec 22nd, 2008 at 1:32 am.

Aamit

Reputation Points: 3

Solved Threads: 15

Posting Whiz

Offline

341 posts
since Apr 2008

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in PHP Forum Timeline: mysql escape string

Next Thread in PHP Forum Timeline: PHP sort control

DaniWeb Message

Cancel Changes

User Name
Password