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1. maxweisel
   Member
   Posted 6 years ago #

   How would I count rows returned if I want to use a SELECT query. I have no idea how to run queries using wordpress's functions and what I want to do it see if there are zero rows returned. so what would this translate to if I wanted to use wordpress functions.

   <?php
   $myvar = mysql_query("SELECT * FROM wp_visitorip WHERE ip='$user_ip'");
   $myvar = mysql_num_rows($myvar);
   if($myvar = 0) {
   // no rows
   } else {
   // at least 1 row
   }
   ?>

   Max

2. maxweisel
   Member
   Posted 6 years ago #

   this would be in a function

3. maxweisel
   Member
   Posted 6 years ago #

   EDIT this would be inside a plugin not a function**

   Max

4. Kafkaesqui
   Moderator
   Posted 6 years ago #

   You can just test on $myvar:

   if($myvar) {

   It should return false if it contains nothing.

   By the way, you might want to look into using the wpdb class in your plugin instead of PHP's regular MySQL functions:

   http://codex.wordpress.org/wpdb_Class

5. maxweisel
   Member
   Posted 6 years ago #

   that is what I am talking about I have no idea how to use those. is there anyway you can translate my snipet of code to use the wpdb class

   Max

6. Kafkaesqui
   Moderator
   Posted 6 years ago #

   First, scope $wpdb to global:

   global $wpdb;

   From there use:

   $myvar = $wpdb->get_results("SELECT * FROM wp_visitorip WHERE ip='$user_ip'");

   Also, if you'd like the plugin to use the blog's table prefix for your 'visitorip' table, scope $table_prefix to global as well, then assign it like so:

   $wpdb->visitorip = $table_prefix . 'visitorip';

   Your query line then becomes:

   $myvar = $wpdb->get_results("SELECT * FROM $wpdb->visitorip WHERE ip='$user_ip'");

7. maxweisel
   Member
   Posted 6 years ago #

   so then myvar would equal a number.

8. Kafkaesqui
   Moderator
   Posted 6 years ago #

   No, $myvar would equal an array holding the results of your query: one or more table records where each record's ip column matched $user_ip. But if there's no match, there's no array.

9. lunabyte
   Member
   Posted 6 years ago #

   If you need the results of the query later on, you don't want to make the myvar variable hold osmething else. You may or may not need the results, just a mention.

   If you do NOT need the results, try this:

   <?php
   $myvar = $wpdb->get_results("SELECT COUNT(*) FROM wp_visitorip WHERE ip='$user_ip'");

   if($myvar == 0)
   {
   // no rows, do whatever.
   }
   else
   {
   // at least 1 row, do something else.
   }
   ?>

   If you do need the result of the query, do this instead.

   $myvar = $wpdb->get_results("SELECT * FROM wp_visitorip WHERE ip='$user_ip'");

   $myvarResults = mysql_num_rows($myvar);
   if($myvarResults == 0)
   {
   // no rows, do whatever.
   }
   else
   {
   // at least 1 row, do something else.
   // here you could run a while loop, whatever.
   }
   ?>

   There's tons of ways to do it. You can check the
   myvar variable in tons of way.

   Like, if (!is_array($myvar)),
   do a num rows, do a count query, whatever.

   Either way, if you do a check for = x, remember in a
   check if something ='s a value, to use double equal signs,
   ($x == $y) or even triple in some cases.

   When in doubt, php.net is a great reference for looking
   up things you might not use everyday.

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