PHPSQLParser\builders\UnionStatementBuilder::build PHP Method

    public function build(array $parsed)
    {
        $sql = '';
        $select_builder = new SelectStatementBuilder();
        $first = true;
        foreach ($parsed['UNION'] as $clause) {
            if (!$first) {
                $sql .= " UNION ";
            } else {
                $first = false;
            }
            $sql .= $select_builder->build($clause);
        }
        return $sql;
    }

 public function create($parsed)
 {
     $k = key($parsed);
     switch ($k) {
         case 'UNION':
             $builder = new UnionStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'UNION ALL':
             $builder = new UnionAllStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'SELECT':
             $builder = new SelectStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'INSERT':
             $builder = new InsertStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'REPLACE':
             $builder = new ReplaceStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'DELETE':
             $builder = new DeleteStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'TRUNCATE':
             $builder = new TruncateStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'UPDATE':
             $builder = new UpdateStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'RENAME':
             $builder = new RenameStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'SHOW':
             $builder = new ShowStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'CREATE':
             $builder = new CreateStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'BRACKET':
             $builder = new BracketStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         case 'DROP':
             $builder = new DropStatementBuilder();
             $this->created = $builder->build($parsed);
             break;
         default:
             throw new UnsupportedFeatureException($k);
             break;
     }
     return $this->created;
 }