code: public function renameColumn($table, $oldName, $newName)
      {
          $quotedTable = $this->db->quoteTableName($table);
          $row = $this->db->createCommand('SHOW CREATE TABLE ' . $quotedTable)->queryOne();
          if ($row === false) {
              throw new Exception("Unable to find column '$oldName' in table '$table'.");
          }
          if (isset($row['Create Table'])) {
              $sql = $row['Create Table'];
          } else {
              $row = array_values($row);
              $sql = $row[1];
          }
          if (preg_match_all('/^\s*`(.*?)`\s+(.*?),?$/m', $sql, $matches)) {
              foreach ($matches[1] as $i => $c) {
                  if ($c === $oldName) {
                      return "ALTER TABLE $quotedTable CHANGE "
                          . $this->db->quoteColumnName($oldName) . ' '
                          . $this->db->quoteColumnName($newName) . ' '
                          . $matches[2][$i];
                  }
              }
          }
          // try to give back a SQL anyway
          return "ALTER TABLE $quotedTable CHANGE "
              . $this->db->quoteColumnName($oldName) . ' '
              . $this->db->quoteColumnName($newName);
      }
docs: Builds a SQL statement for renaming a column.
  @param string $table the table whose column is to be renamed. The name will be properly quoted by the method.
  @param string $oldName the old name of the column. The name will be properly quoted by the method.
  @param string $newName the new name of the column. The name will be properly quoted by the method.
  @return string the SQL statement for renaming a DB column.
  @throws Exception