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accessing an empty querry result

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Join Date: Oct 2008

Posts: 42

Reputation: marcmm is an unknown quantity at this point

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marcmm

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Light Poster

accessing an empty querry result

Dec 20th, 2008

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.

 Help with Code Tags 
 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?

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Join Date: Apr 2008

Posts: 293

Reputation: Aamit has a little shameless behaviour in the past

Solved Threads: 11

Aamit

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Posting Whiz in Training

Re: accessing an empty querry result

Dec 20th, 2008

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

 Help with Code Tags 
 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.

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Join Date: Dec 2008

Posts: 20

Reputation: manish.s is an unknown quantity at this point

Solved Threads: 1

manish.s

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Newbie Poster

Re: accessing an empty querry result

Dec 21st, 2008

Aamit,

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

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Join Date: Apr 2008

Posts: 293

Reputation: Aamit has a little shameless behaviour in the past

Solved Threads: 11

Aamit

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Posting Whiz in Training

Re: accessing an empty querry result

Dec 22nd, 2008

 Help with Code Tags 
 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

}