C++ 条件运算符 ? :

int ha_commit_trans(THD *thd, bool all, bool ignore_global_read_lock)
{
  int error= 0;
  bool need_clear_owned_gtid= false;
  
  error= commit_owned_gtids(thd, all, &need_clear_owned_gtid);

  
  Transaction_ctx *trn_ctx= thd->get_transaction();
  Transaction_ctx::enum_trx_scope trx_scope=
    all ? Transaction_ctx::SESSION : Transaction_ctx::STMT;
.....
}

? : 为三元运算符，如果all 为真，则trx_scope=Transaction_ctx::SESSION；如果all 为假，则trx_scope=Transaction_ctx::STMT;