Question

要求：需要弄清楚哪些LoginID Default设置为1但0设置为Default。规则是，所有LoginID都可以0作为1或0，但对于给定的LoginID，必须至少有一条记录LoginID Default A 0 A 1 A 1 B 1 B 1 B 1 B 1 C 0 D 0 D 1 E 0 E 1 E 1。

表格如下：

dbHelper = new DatabaseHandler(view.getContext());

dbHelper.deleteRamz(ramz.get_id());//this should be your object id
ramzList.remove(position);
notifyItemRemoved(position);

notifyItemRangeChanged(position,getItemCount());
Log.i("item deleted", String.valueOf(ramzList.size()));

Answer 1

最简单的解决方案是使用MINUS运算符。

select loginID from your_table where default = 1
minus
select loginID from your_table where default = 0

这会生成一组登录ID，其default 1但0没有。

Answer 2

我倾向于使用-和facebookLogin(): Promise<any> { return this.facebook.login(['email']) .then( (response) => { const facebookCredential = firebase.auth.FacebookAuthProvider .credential(response.authResponse.accessToken); this.afAuth.auth.signInWithCredential(facebookCredential) .then( userData => { this.userProfileRef.child(userData.uid).set({ hypes: 23, name: userData.displayName, image: userData.photoURL, friends: userData.friends, }); this.userUID = userData.uid; }) .catch((error) => { console.log("Firebase failure: " + JSON.stringify(error)); }); }) .catch((error) => { console.log(error) }); }}来解决此类问题：

group by

Answer 3

你可能正在寻找一些简单的东西：

SELECT DISTINCT LoginID
  FROM yourtable
 WHERE Default = 1
   AND LoginID NOT IN ( SELECT LoginID FROM yourtable WHERE Default = 0)

加入同一张桌子

3 个答案: