Question

I get the number of rows on a constrained record by using

$table1="tab1";
        $table2="tab2";
$query=sprintf("SELECT '%s'.* FROM '%s' JOIN '%s' ON ('%s'.id='%s'.id)",
               $table1,
               $table1,
               $table2,
               $table1,
               $table2);
        $query=$this->db->query($query);
        return $query->num_rows();

and I come up with the following error, I am using latest XAMPP with mysql version 5.1

Error Number: 1064

You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near ‘.* FROM ‘tab1’ JOIN ‘tab2’ ON
(‘tab1′.userid=’tab2′.userid)’ at line 1

SELECT ‘tab1’.* FROM ‘tab1’ JOIN ‘tab2’ ON
(‘tab1′.userid=’tab2’.userid)

Filename: A:\CodeIgniter_2.1.0\system\database\DB_driver.php

Line Number: 330

UPDATE

$query=sprintf("SELECT `%s`.* FROM `%s` JOIN `%s` ON (`%s`.id=`%s`.id) LIMTI `%d`, `%d`",
                   $table1,
                   $table1,
                   $table2,
                   $table1,
                   $table2,
                   $num1,
                   $num2);

the error is

Error Number: 1327

Undeclared variable: 5

SELECT tab1.* FROM tab1 JOIN tab2 ON
(tab1.userid=tab2.userid) LIMIT 5,0

Filename: A:\CodeIgniter_2.1.0\system\database\DB_driver.php

Line Number: 330

Answer 1

Try this code.

$table1="tab1";
        $table2="tab2";
$query=sprintf("SELECT `%s`.* FROM `%s` JOIN `%s` ON (`%s`.id=`%s`.id)",
               $table1,
               $table1,
               $table2,
               $table1,
               $table2);
        $query=$this->db->query($query);
        return $query->num_rows();

I think your second query should be like this.

$query=sprintf("SELECT `%s`.* FROM `%s` JOIN `%s` ON (`%s`.id=`%s`.id) LIMTI %d, %d",
                   $table1,
                   $table1,
                   $table2,
                   $table1,
                   $table2,
                   $num1,
                   $num2);