c.AfterExpression.Build(builder)
		}
	}
}

const (
	PrimaryKey   string = "~~~py~~~" // primary key
	CurrentTable string = "~~~ct~~~" // current table
	Associations string = "~~~as~~~" // associations
)

var (
	currentTable  = Table{Name: CurrentTable}
	PrimaryColumn = Column{Table: CurrentTable, Name: PrimaryKey}
)

// Column quote with name
type Column struct {
	Table string
	Name  string
	Alias string

            if (elementName.equals("table")) {
                if (currentTable != null) {
                    throw new UnsupportedOperationException("A table within a table is not supported.");
                }
                currentTable = document.createElement("table");
                nodes.push(currentTable);
                return true;
            }
            if (elementName.equals("tr")) {

	if len(from.Tables) > 0 {
		for idx, table := range from.Tables {
			if idx > 0 {
				builder.WriteByte(',')
			}

			builder.WriteQuoted(table)
		}
	} else {
		builder.WriteQuoted(currentTable)
	}

	for _, join := range from.Joins {
		builder.WriteByte(' ')
		join.Build(builder)
	}
}

// MergeClause merge from clause
func (from From) MergeClause(clause *Clause) {
	clause.Expression = from

func (update Update) Build(builder Builder) {
	if update.Modifier != "" {
		builder.WriteString(update.Modifier)
		builder.WriteByte(' ')
	}

	if update.Table.Name == "" {
		builder.WriteQuoted(currentTable)
	} else {
		builder.WriteQuoted(update.Table)
	}
}

// MergeClause merge update clause
func (update Update) MergeClause(clause *Clause) {
	if v, ok := clause.Expression.(Update); ok {

	if insert.Modifier != "" {
		builder.WriteString(insert.Modifier)
		builder.WriteByte(' ')
	}

	builder.WriteString("INTO ")
	if insert.Table.Name == "" {
		builder.WriteQuoted(currentTable)
	} else {
		builder.WriteQuoted(insert.Table)
	}
}

// MergeClause merge insert clause
func (insert Insert) MergeClause(clause *Clause) {
	if v, ok := clause.Expression.(Insert); ok {

		if err := stmt.Parse(oldName); err == nil {
			oldTable = m.CurrentTable(stmt)
		} else {
			return err
		}
	}

	if v, ok := newName.(string); ok {
		newTable = clause.Table{Name: v}
	} else {
		stmt := &gorm.Statement{DB: m.DB}
		if err := stmt.Parse(newName); err == nil {
			newTable = m.CurrentTable(stmt)
		} else {
			return err
		}
	}

        return;
      }

      while (nextSegmentIndex >= 0) {
        currentSegment = segments[nextSegmentIndex--];
        if (currentSegment.count != 0) {
          currentTable = currentSegment.table;
          nextTableIndex = currentTable.length() - 1;
          if (nextInTable()) {
            return;
          }
        }
      }
    }

					clauseSelect.Columns[idx] = clause.Column{Table: db.Statement.Table, Name: dbName}
				}
			}

			specifiedRelationsName := map[string]string{clause.CurrentTable: clause.CurrentTable}
			for _, join := range db.Statement.Joins {
				if db.Statement.Schema != nil {
					var isRelations bool // is relations or raw sql
					var relations []*schema.Relationship

func (db *DB) First(dest interface{}, conds ...interface{}) (tx *DB) {
	tx = db.Limit(1).Order(clause.OrderByColumn{
		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
	})
	if len(conds) > 0 {
		if exprs := tx.Statement.BuildCondition(conds[0], conds[1:]...); len(exprs) > 0 {
			tx.Statement.AddClause(clause.Where{Exprs: exprs})
		}
	}

        return;
      }

      while (nextSegmentIndex >= 0) {
        currentSegment = segments[nextSegmentIndex--];
        if (currentSegment.count != 0) {
          currentTable = currentSegment.table;
          nextTableIndex = currentTable.length() - 1;
          if (nextInTable()) {
            return;
          }
        }
      }
    }