remove duplicate camma from mysql query - php

Question

I am trying to fetch data with mulyiple value with Mysql IN operator but problem I am getting to much (,,,).
Here is my query :
$get_id = "select rel_blog from pages";
$resu = mysql_query($get_id);
$p_id="";
$rel_b="";
$i = 1;
while ($page_id = mysql_fetch_array($resu)){
$p_id.= $page_id['page_id'];
$rel_b.= $page_id['rel_blog'];
}
$p_id."<br>";
echo $rel_b."<br>";
echo $getblog = "SELECT * FROM pages WHERE rel_blog IN ($rel_b) order by add_date desc limit 7";
Ouery output is Like this this is not proper form so please help me .
SELECT * FROM pages WHERE rel_blog IN
(,114,93,126108default,,,,default,,,,default,,default,,,default,,default,,,,,,,default,,default,,,default,,default,,,,,,,,,,,,,,,,,,,,,,,,,,123,145,144,148,81,107default,,,,,default,,,,,,145,138,118default,,,,,,default,,,,,,,default,,,,,,,default,,,,,,,default,,,118default,,,,default,,,,,,,,default,,,,,,,,,default,,default,,,,,,,,default,,,,,,,,,default,,default,,,,,default,,,,,,default,,,,,,,,,default,,,,,,,,default,,,,,default,,,,,,,123,122,125,113default,,,default,,,default,,124,145140default,,,,,,,,,,,,,default,,,,,,,,default,,,default,,,default,,,,default,,,,default,,default,,,,default,,,default,,,default,,default,,,,,,,default,,,,,,default,,,,default,,,,,,default,,,default,,,,137default,,,,,,,default,,,default,,,default,,,,,,default,,,,,,,,,,default,,,,,,,,82,83default,,,,,,default,,,,default,,,,default,,,default,,,default,,,,default,,,,default,,,,default,,,,default,,,default,,,,default,,,,default,,,default,,,default,,,,,,default,,,,,,default,,,,,default,,,default,,,,,default,,,,,default,,,,default,,,default,,default,,default,,default,,,,,,,default,,,,default,,default,,,,default,,,,default,,,,default,,,,,default,,,,default,,,,,default,,,,,,,default,,,,default,,,,,default,,,,,,default,,,,,,,default,,,,,,default,,,,,,,default,,default,,default,,,,,default,,,default,,,default,,,default,,,,default,114,default,,,,,,117,116default,,,,,default,,,,117,116default,,,,default,,,,default,,,,,default,,,,default,,,,,default,,,,default,,,default,,default,,,,,,default,,,,,,default,,,,,108default,,,,118,129,121,143,80,82,81,148,117,146,107,88,118,82,80,81,148,143,123,118,107,142,116,110,128,127,111,109,125,113,123,118,85,118,128,109,126,93,114,82,142,108,111,90,113,123,144,148,108,107,142,116,115,110,128,127,113,118,144,146,80,148,107,143,135,125,143,110,115,118,132,146,80,123,81,148,107,116,108,109,125,135,113,123,144,118,116,108,127,147,125,123,144,129,107,142,112,116,135,113,123,144,132,118,107,85,123,144,118,82,148,107,123,132,146,148,107,108,122,89,136,146,80,81,117,148,142,107,110,147,119,82,80,145,129,146,80,148,107,111,109,125,113,123,118,148,81,107,131,115,109,121,125,135,113,123,144,107,131,126,93,141,114,124,139,113,91,144,118,81,117,148,107,142,115,143,135,91,118,142,116,87,143,140,123,144,132,145,129,146,82,80,117,91,118,148,137,113,141,93,143,136,123,144,146,82,118,148,85,112,108,127,122,87,143,141,91,144,146,80,82,81,117,148,107,115,109,91,129,146,82,80,117,148,81,142,107,110,130,138,89,126,113,default,default,118,146,82,81,148,107,142,115,109,126,default,123,144,145,80,146,82,81,117,142,128,138,135,93,140,123,144,145,132,82,80,117,83,142,130,140,145,129,82,80,81,108,111,138,89,143,125,145,123,118,82,80,81,117,88,112,108,147,139,119,140,123,144,118,80,82,81,142,107,85,108,115,114,144,118,129,146,80,81,83,120,148,107,142,128,127,110,115,91,123,145,82,117,146,81,80,148,82,80,117,81,148,83,120,107,142,88,131,118,129,146,80,117,107,83,88,142,130,89,125,139,134,113,145,144,118,132,123,82,80,146,81,148,83,123,91,137,140,134,139,113,141,124,93140,150,150)
order by add_date desc limit 7

Answer 1

Actually I can't figure out how you are getting even a single comma... This is how you can try it out.
$get_id = "select rel_blog,page_id from pages";
$resu = mysql_query($get_id);
$p_id="";
$rel_b="";
$i = 1;
while ($page_id = mysql_fetch_array($resu)){
$p_id.= $page_id['page_id'];
if($page_id['rel_blog']!=="" && $page_id['rel_blog']==="default") {
$rel_b.= $page_id['rel_blog'] .",";
}
}
$p_id."<br>";
$rel_b = substr($rel_b,0,-1); // get rid of the last comma
echo $rel_b."<br>";
echo $getblog = "SELECT * FROM pages WHERE rel_blog IN ($rel_b) order by add_date desc limit 7";

Answer 2

You can do this before your query.
$rel_b = preg_replace('/,+/', ',', trim($rel_b, ','));
This will remove repeated commas as well as commas from beginning and end of the string.

Answer 3

Try using implode():
$get_id = "select rel_blog from pages";
$resu = mysql_query($get_id);
$p_id = array();
$rel_b = array();
$i = 1;
while ($page_id = mysql_fetch_array($resu)){
$p_id[] = $page_id['page_id'];
$rel_b[] = $page_id['rel_blog'];
}
$p_id = implode(',', $p_id);
$rel_b = implode(',', rel_b);
echo $getblog = "SELECT * FROM pages WHERE rel_blog IN ($rel_b) order by add_date desc limit 7";