Question

I’m trying to update a row with a serialized array, but the row is not updating when I run the SQL statement below.

However when I just use a word like TEST instead it updates.

Any help on clearing this up would be greatly appreciated.

Returns 0 rows affected:

UPDATE lists SET col1 = 'a:9:{i:0;s:7:"English";i:1;s:7:"Spanish";i:2;s:6:"Korean";i:3;s:4:"Thai";i:4;s:0:"";i:5;s:0:"";i:6;s:0:"";i:7;s:0:"";i:8;s:0:"";}' WHERE list_id =  '6'

Updates row correctly:

UPDATE lists SET col1 = 'TEST' WHERE list_id =  '6'

Below is the Codeigniter PHP function:

public function update_field($table, $field, $value, $whereField = FALSE, $whereValue = FALSE )
{

$user_id = $this->session->userdata('user_id');
if ($whereField === FALSE) {
$sql = "UPDATE $table SET $field = '$value'";
$query =  $this->db->query($sql);
} else {

    $data = array(
        $field => $value
    );

    $this->db->where($whereField, $whereValue);
    $this->db->update($table, $data);

}

if ($this->db->_error_message()) {

    echo 'Error Num: ' . $this->db->_error_number();  //returns 0 if query successful/no error
    echo '<br />Message: ' . $this->db->_error_message(); 
}

}

Answer 1

the line is fine.

if you will try to update a field to it’s current value (ie you make no actual changes) then you will get 0 updated rows.

for example, if i have an employees table:

employees
id    name      city
1     John      London

UPDATE `employees` SET `city` = "London" WHERE `id` = 1

// 0 rows affected

if you make no actual changes it returns 0