Trying to construct an sql query string

Hello,

I am making a section for my handmade themes on my site(anyway this is not the point). I am trying to construct a sql_query string but the output is mostly 0 I am not new to php but probably I am missing something out in the crowd... The below code explains almost everything:

<?php

include "database_connection_general.inc";
      $property_id = "2";
      // I need to get theme ids which has a property_id = 2
      $sql_theme_id_get = mysql_query("SELECT theme_id FROM theme_property_relation WHERE property_id='$property_id'");
      while ($row = mysql_fetch_array($sql_theme_id_get)) {
          $theme_id = $row["theme_id"];
            $sql_tail_query += "theme_id='$theme_id' AND ";
      }

            $sql_head_query = "SELECT * FROM theme WHERE "; // adding the head part for the query
            $sql_extended_query = $sql_head_query + $sql_tail_query; // adding the tail part but there is a "AND " at the end that must be cropped!!!
            $sql_total_query = substr($sql_extended_query, 0, -4); // cropping the last 4 characters "AND "
            $sql_final_query = $sql_total_query + " ORDER BY theme_added DESC LIMIT 0 , 10"; // adding the order part
            
            echo "$sql_final_query";

            /* Output should be like:
            SELECT * FROM theme WHERE theme_id='2' AND theme_id='15' AND theme_id='74' AND theme_id='103' ORDER BY theme_added DESC LIMIT 0 , 10
            
            but getting 0
            */
      
?>

Thank you,
cemlouisAsked:
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Steve BinkCommented:
String concatenation is done with the period.

            $sql_head_query = "SELECT * FROM theme WHERE "; // adding the head part for the query
            $sql_extended_query = $sql_head_query . $sql_tail_query; // adding the tail part but there is a "AND " at the end that must be cropped!!!
            $sql_total_query = substr($sql_extended_query, 0, -4); // cropping the last 4 characters "AND "
            $sql_final_query = $sql_total_query . " ORDER BY theme_added DESC LIMIT 0 , 10"; // adding the order part
0

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Steve BinkCommented:
Also:

 $sql_tail_query .= "theme_id='$theme_id' AND ";
0
cemlouisAuthor Commented:
Hello routinet,

thank you, I get ashamed of making this mistake :( I am messing with C# these days probably that's the source of the mistake...

Regards,
0
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