Insert-update utf8 string sql server + codeigniter - sql-server

Question

I am using Codeigniter 2.1 and Microsoft Sql Server. When I try to insert UTF8 strings in database I get ??? characters. To connect to database I use SqlSrv driver.

Answer 1

Small change in SqlSrv driver solves the problem with unicode.
Just add _make_unicode function code to /system/database/sqlsrv/sqlsrv_driver.php and replace the code for _insert and _update functions
/**
* #param mixed $value
*/
function _make_unicode($value){
if(is_string($value) && $value!="NULL")return "N".$value;
else return $value;
}
/**
* Insert statement
*
* Generates a platform-specific insert string from the supplied data
*
* #access public
* #param string the table name
* #param array the insert keys
* #param array the insert values
* #return string
*/
function _insert($table, $keys, $values)
{
$values_string = "";
for($i=0;$i<count($values);$i++){
if($i==0){
$values_string.= $this->_make_unicode($values[$i]);
}else{
$values_string.= ", ".$this->_make_unicode($values[$i]);
}
}
return "INSERT INTO ".$this->_escape_table($table)." (".implode(', ', $keys).") VALUES ({$values_string})";
}
// --------------------------------------------------------------------
/**
* Update statement
*
* Generates a platform-specific update string from the supplied data
*
* #access public
* #param string the table name
* #param array the update data
* #param array the where clause
* #param array the orderby clause
* #param array the limit clause
* #return string
*/
function _update($table, $values, $where)
{
foreach($values as $key => $val)
{
$valstr[] = $key." = ".$this->_make_unicode($val);
}
return "UPDATE ".$this->_escape_table($table)." SET ".implode(', ', $valstr)." WHERE ".implode(" ", $where);
}
// --------------------------------------------------------------------

Answer 2

Adding to Alex's answer (sorry not enough reputation to comment). Here are the same functions for CodeIgniter 3.1.1.
_insert_batch
/**
* Insert batch statement
*
* Generates a platform-specific insert string from the supplied data.
*
* #param string $table Table name
* #param array $keys INSERT keys
* #param array $values INSERT values
* #return string|bool
*/
protected function _insert_batch($table, $keys, $values)
{
// Multiple-value inserts are only supported as of SQL Server 2008
if (version_compare($this->version(), '10', '>='))
{
foreach($values as &$value) {
$value = $this->_make_unicode($value);
}
return parent::_insert_batch($table, $keys, $values);
}
return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
}
_update
/**
* Update statement
*
* Generates a platform-specific update string from the supplied data
*
* #param string $table
* #param array $values
* #return string
*/
protected function _update($table, $values)
{
foreach ($values as &$value) {
$value = $this->_make_unicode($value);
}
$this->qb_limit = FALSE;
$this->qb_orderby = array();
return parent::_update($table, $values);
}