AlterQuery  dst_00753 (children 2)
 ExpressionList (children 3)
  AlterCommand DROP_COLUMN (children 1)
   Identifier x
  AlterCommand MODIFY_COLUMN (children 1)
   ColumnDeclaration y (children 1)
    DataType String
  AlterCommand ADD_COLUMN (children 1)
   ColumnDeclaration z (children 2)
    DataType String
    Literal \'DEFZ\'
 Identifier dst_00753
