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+--- Thread: drop_column() support for sqlite3_forge driver (/showthread.php?tid=75330)
drop_column() support for sqlite3_forge driver - nplaviola - 01-27-2020
Any chance of getting the drop_column() option added to the sqlite3_forge driver? Can someone help me piece it together if not? is it as simple as uncommenting the commented section below? (it's clearly not, haha). Thank you!
Existing method:
PHP Code:
/**
* ALTER TABLE
*
* @todo implement drop_column(), modify_column()
* @param string $alter_type ALTER type
* @param string $table Table name
* @param mixed $field Column definition
* @return string|string[]
*/
protected function _alter_table($alter_type, $table, $field)
{
if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
{
// drop_column():
// BEGIN TRANSACTION;
// CREATE TEMPORARY TABLE t1_backup(a,b);
// INSERT INTO t1_backup SELECT a,b FROM t1;
// DROP TABLE t1;
// CREATE TABLE t1(a,b);
// INSERT INTO t1 SELECT a,b FROM t1_backup;
// DROP TABLE t1_backup;
// COMMIT;
return FALSE;
}
return parent::_alter_table($alter_type, $table, $field);
}
RE: drop_column() support for sqlite3_forge driver - nplaviola - 01-28-2020
(01-27-2020, 02:40 PM)nplaviola Wrote: Any chance of getting the drop_column() option added to the sqlite3_forge driver? Can someone help me piece it together if not? is it as simple as uncommenting the commented section below? (it's clearly not, haha). Thank you!
Existing method:
PHP Code:/**
* ALTER TABLE
*
* @todo implement drop_column(), modify_column()
* @param string $alter_type ALTER type
* @param string $table Table name
* @param mixed $field Column definition
* @return string|string[]
*/
protected function _alter_table($alter_type, $table, $field)
{
if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
{
// drop_column():
// BEGIN TRANSACTION;
// CREATE TEMPORARY TABLE t1_backup(a,b);
// INSERT INTO t1_backup SELECT a,b FROM t1;
// DROP TABLE t1;
// CREATE TABLE t1(a,b);
// INSERT INTO t1 SELECT a,b FROM t1_backup;
// DROP TABLE t1_backup;
// COMMIT;
return FALSE;
}
return parent::_alter_table($alter_type, $table, $field);
}
I wrote a workaround in my model and thought I'd share the meat of it in case anyone else runs into this. It's not very sophisticated but it gets the job done:
PHP Code:
$this->db->trans_start();
$this->db->query('CREATE TEMPORARY TABLE t1_backup(a,b);');
$this->db->query('INSERT INTO t1_backup SELECT a,b FROM t1;');
$this->db->query('DROP TABLE t1;');
$this->db->query('CREATE TABLE t1(a,b);');
$this->db->query('INSERT INTO t1 SELECT a,b FROM t1_backup;');
$this->db->query('DROP TABLE t1_backup;');
$this->db->trans_complete();
//check for the existence of the field to verify it's gone
if ($this->db->field_exists($old_field, $table_name))
{
//do something
}
The query strings are dynamic in my code but I figure that's easy enough to do yourself.