array to string conversion error in codeigniter 3.0.1 - php

Question

I have the following error message while updating my records in database
Severity: Notice
Message: Array to string conversion
Filename: database/DB_query_builder.php
Line Number: 662
Backtrace:
File: C:\xampp\htdocs\Site\application\models\class_model.php Line: 48
Function: where
File: C:\xampp\htdocs\Site\application\controllers\class_con.php Line:
107 Function: update
File: C:\xampp\htdocs\Site\index.php Line: 292 Function: require_once
here my controller
function edit($id)
{
$rules = [
[
'field' => 'classname',
'label' => 'Class Name',
'rules' => 'trim|required'
],
[
'field' => 'inchargename',
'label' => 'Incharge Name',
'rules' => 'trim|required'
],
[
'field' => 'classstrength',
'label' => 'Class Strength',
'rules' => 'trim|required'
]
];
$this->form_validation->set_rules($rules);
$class = $this->class_model->find($id)->row();
if($this->form_validation->run() == FALSE)
{
$this->load->view('admin/class/classEdit',array('class'=>$class));
}
else
{
$data['classname'] = set_value('classname');
$data['inchargename'] = set_value('inchargename');
$data['classstregth'] = set_value('classstregth');
$this->class_model->update($id,$data);
$this->session->set_flashdata('message','Class has been Updated Successfully');
redirect('class_con/index');
}
}
and here's my model
public function find($id) {
$this->db->where('id',$id);
$row = $this->db->get('class');
return $row;
}
function update($data, $id)
{
try{
$this->db->where('id',$id);
$this->db->update('class', $data);
return true;
}
catch(Execption $e){
echo $e->getMessage();
}
}
and here is my view
<?php echo form_open_multipart('class_con/edit/'.$class->id); ?>
<div class="form-group" id="register-login-group">
<label for="classname">Class Name</label>
<div class="input-group">
<input type="text" class="form-control" id="classname" name="classname" value="<?php echo $class->classname; ?>" placeholder="Class Name">
<div class="input-group-addon"><i class="fa fa-pencil"></i></div>
</div>
</div>
<div class="form-group" id="register-login-group">
<label for="classname">Incharge Name</label>
<div class="input-group">
<input type="text" class="form-control" id="inchargename" name="inchargename" value="<?php echo $class->inchargename; ?>" placeholder="Incharge Name">
<div class="input-group-addon"><i class="fa fa-pencil"></i></div>
</div>
</div>
<div class="form-group" id="register-login-group">
<label for="classname">Class Strength</label>
<div class="input-group">
<input type="text" class="form-control" id="classstrength" name="classstrength" value="<?php echo $class->classstrength; ?>" placeholder="Class Stregth">
<div class="input-group-addon"><i class="fa fa-pencil"></i></div>
</div>
</div>
<button type="submit" class="btn btn-primary">Save</button>
<?=anchor('class_con/index','Cancel',['class'=>'btn btn-warning'])?>
<?php echo form_close(); ?>

Answer 1

In your controller You call the update method in model by this line :
$this->class_model->update($id,$data);
but in your Model you have defined function as :
function update($data, $id)
{
try{
$this->db->where('id',$id);
$this->db->update('class', $data);
return true;
}
catch(Execption $e){
echo $e->getMessage();
}
}
the problem is with the order of parameter's that you have passed :
change it to :
$this->class_model->update($data,$id);

Answer 2

Just remove ->row() from
$class = $this->class_model->find($id)->row();
Instead use
$class = $this->class_model->find($id);
foreach ($class->result() as $row)
{
echo $row->colunn_name;
}
And set_value()
Permits you to set the value of an input form or textarea. You must
supply the field name via the first parameter of the function.
So instead
$data['classname'] = set_value('classname');
$data['inchargename'] = set_value('inchargename');
$data['classstregth'] = set_value('classstregth');
Use to store value in $data array
$data['classname'] = 'classname';
$data['inchargename'] = 'inchargename';
$data['classstregth'] = 'classstregth';

Answer 3

It seems there is a bug in your query.
Please trace error using following steps.
1) use $this->db->last_query(); which prints your query....
2) Run that query in sql, it gives the appropriate row or not.
3) if query works properly, now print_r the o/p variable and trace weather it gives the result or not.