Codeigniter - Batch Update with Multiple Where Conditions

Question

For starters, the Codeigniter documentation on update_batch does not exist. kenjis was kind enough to provide some documentation and submit it to the repository. Hopefully t

Answer 1

I am using codeigniter 3.1.5 and had the same problem, but I solved my problem as follows:

$data = array(
    array(
        'title' => 'My title' ,
        'name' => 'My Name 2' ,
        'date' => 'My date 2'
    ),
    array(
        'title' => 'Another title' ,
        'name' => 'Another Name 2' ,
        'date' => 'Another date 2'
    )
);

$this->db->where('name','My Name 2');
$this->db->update_batch('mytable', $data, 'title');

Produces it:

// Produces:
// UPDATE `mytable`
// SET `name` = CASE
//     WHEN `title` = 'Another title' THEN 'Another Name 2'
//     WHEN `title` = 'My title' THEN 'My Name 2'
//     ELSE `name`
// END,
//     `date` = CASE 
//     WHEN `title` = 'My title' THEN 'My date 2'
//     WHEN `title` = 'Another title' THEN 'Another date 2'
//     ELSE `date`
// END
//     WHERE `title` IN ('My title','Another title')
// AND `name` = 'My Name 2'

UPDATE

I had a problem trying to add more than 100 records with update_batch, for example:

$data = [1=>a,2=>b ... 200=>zz];

First call (with WHERE):

// Produces:
// UPDATE `mytable`
// SET `name` = CASE
//    WHEN `title` = 'My title' THEN 'My Name 2'
//    WHEN `title` = 'Another title' THEN 'Another Name 2'
//    ELSE `name`
// END,
//  `date` = CASE 
//    WHEN `title` = 'My title' THEN 'My date 2'
//    WHEN `title` = 'Another title' THEN 'Another date 2'
//    ELSE `date`
// END
//    WHERE `title` IN ('My title','Another title')
//    AND `name` = 'My Name 2'

Second call on (Without WHERE):

// Produces:
// UPDATE `mytable`
// SET `name` = CASE
//      WHEN `title` = 'My title' THEN 'My Name 2'
//      WHEN `title` = 'Another title' THEN 'Another Name 2'
//      ELSE `name`
// END,
//      `date` = CASE 
//      WHEN `title` = 'My title' THEN 'My date 2'
//      WHEN `title` = 'Another title' THEN 'Another date 2'
//      ELSE `date`
// END
//      WHERE `title` IN ('My title','Another title')

Try this:

$chunk1 = array_chunk($data,100);
for($i=0;$i < count($chunk1);$i++) {
   $this->upload_model->update_data($chunk1[$i],'My Name 2');
}

Model:

public function update_data($data='',$name=''){
   $this->db->where('name',$name);
   $this->db->update_batch('mytable', $data, 'title');
}

Answer 2

You can't add multiple where clauses to update_batch(). It only accepts a string as the third parameter for the where clause so I'm sure there's no way to do this the way the method is currently written.

From the source:

/**
 * Update_Batch
 *
 * Compiles an update string and runs the query
 *
 * @param   string  the table to retrieve the results from
 * @param   array   an associative array of update values
 * @param   string  the where key
 * @return  object
 */
public function update_batch($table = '', $set = NULL, $index = NULL)

Answer 3

Multiple where conditions are broken in update_batch because the WHERE query is being cleared in the batch loop.

Here is the batch update loop:

        for ($i = 0, $total = count($this->qb_set_ub); $i < $total; $i += $batch_size)
        {
            if ($this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set_ub, $i, $batch_size), $index)))
            {
                $affected_rows += $this->affected_rows();
            }

            $this->qb_where = array();
        }

Notice that the passed WHERE conditions are cleared by $this->qb_where = array();.

In CodeIgniter v3.1.10, the offending line is on 1940 in DB_query_builder.php. This produces a very unexpected behavior where WHERE conditions work for the first batch processed (default 100) and fail for subsequent batches.

There are two possible solutions:

1. Use the 4th batch_size parameter of update_batch and pass a large number such as 100,000 so all the queries are processed in the first batch and the WHERE condition is not cleared.
2. Update the offending line to restore the initial WHERE conditions.

Code for Solution #2:

        // Save initial where conditions.
        $where_holder = $this->qb_where;
        // Batch this baby
        $affected_rows = 0;
        for ($i = 0, $total = count($this->qb_set_ub); $i < $total; $i += $batch_size)
        {
            if ($this->query($this->_update_batch($this->protect_identifiers($table, TRUE, NULL, FALSE), array_slice($this->qb_set_ub, $i, $batch_size), $index)))
            {
                $affected_rows += $this->affected_rows();
            }

            // Restore intial where conditions.
            $this->qb_where = $where_holder;
        }

Hope this helped!