Posgtresql add column after or before.

pg_add_column.php

// Warning! You lose all constraight's
// All depended views NOT updating

function AddColumnPos( $table_name, $pos, $name, $data_type )
{
  db::Query("BEGIN");
  db::Query("LOCK TABLE {$table_name} IN ACCESS EXCLUSIVE MODE");
  db::Query("SET CONSTRAINTS ALL DEFERRED");

  $cols = db::Query("SELECT column_name as name, data_type as type FROM information_schema.columns WHERE table_name='{$table_name}'");
  assert($cols);

  $salt = md5(time());

  // Rename all columns (temporary)
  for ($i = $pos; $i < count($cols); $i++)
    db::Query("ALTER TABLE {$table_name} RENAME {$cols[i].name} TO {$cols[$i].name}_{$salt}");

  // Add new column
  db::Query("ALTER TABLE {$table_name} ADD {$name} {$data_type}");

  // Dublicate columns
  for ($i = $pos; $i < count($ret); $i++)
    db::Query("ALTER TABLE {$table_name} ADD {$cols[i].name} {$cols[i].type}");

  // Copy data
  for ($i = $pos; $i < count($ret); $i++)
    db::Query("UPDATE {$table_name} SET {$cols[i].name}={$cols[i].name}_{$salt}");

  // TODO:
  // Apply constraight's
  // Find foreign keys and rebind

  // Remove orign columns
  for ($i = $pos; $i < count($cols); $i++)
    db::Query("ALTER TABLE {$table_name} DROM {$cols[$i].name}_{$salt}");

  db::Query("COMMIT");
}