[RESOLVED] creating part of a query from string

[qadeer_ahmad]

Hi,
i have a string containing tables name dynamicaly like

$str="tbl1,tbl2,tbl3,tbl4";
now from here i want to create a part of query like

tbl1.id=tbl2.id and tbl2.id=tbl3.id and tbl3.id=tbl4.id

id is fixed value so no worry about it.

thanks

[iamtheironman]

$str="tbl1,tbl2,tbl3,tbl4";


$a=explode(",",$str);  // becomes $a[0]=='tbl1', $a[1]=='tbl2', etc.
$asize=sizeof($a);

$sql='';
for($i=0;$i<($asize-1);$i++)
{ 	$sql.= $a[$i] . '.id=' . $a[$i+1] . '.id and ';
}

// remove last ' and '
$sql=substr($sql,0,-5);
echo "<hr>".$sql;

[cbj4074]

Why use a string when an array is much better suited for the job?

I'd do something like this:

$tables = array('tbl1', 'tbl2', 'tbl3', 'tbl4');

$query = 'SELECT * FROM your_table WHERE '; //finish the first part of your query here

for ($i = 0; $i < count($tables) - 1; $i++) {
	$query .= $tables[$i] . '.id=' . $tables[$i+1] . '.id';
	//Add this part to prevent an ' AND ' from being added in the last iteration.
	if ($i != count($tables) - 2) {
		$query .= ' AND ';
	}
}

echo $query;

[cbj4074]

Damn you, Iron Man! You have faster fingers than I, my friend =)

[iamtheironman]

huh what... do we win anything here for posting a solution first? :p

(that should be a drool not a strawberry)