新IT討論區(3) - 避難所
媽咪做社工
1001 回覆
2 Like
3 Dislike
第 1 頁第 2 頁第 3 頁第 4 頁第 5 頁第 6 頁第 7 頁第 8 頁第 9 頁第 10 頁第 11 頁第 12 頁第 13 頁第 14 頁第 15 頁第 16 頁第 17 頁第 18 頁第 19 頁第 20 頁第 21 頁第 22 頁第 23 頁第 24 頁第 25 頁第 26 頁第 27 頁第 28 頁第 29 頁第 30 頁第 31 頁第 32 頁第 33 頁第 34 頁第 35 頁第 36 頁第 37 頁第 38 頁第 39 頁第 40 頁第 41 頁
missing handbro day 0
done la
now prepare proactive works
now prepare proactive works
廢post借嚟派下膠
Don't use separator to performance storing a list to achieve one to many.
Hard to maintains the list(update, insert, delete, select)
fk column has maximum if as string
Solution build a intersection table. MySQL foreign key will automatically indexed and the fk should be reference another table index.
----------
Tree structure design
Don't use one child to one parent(self referencing) a.index a.parent reference a.index[adjacency list]
Hard to maintains(remove subtree need find the leaves first)
TBC(need deep study the example if have time)
1.Recursion query With clause(check mysql support or not)
2.Path variable a column set parent/parent/
(same problem as jaywalking)
3. CLOSURE Table (intersection table easiest)
4. Nested set(left node right node; real building C++ B-Tree)
Don't use separator to performance storing a list to achieve one to many.
Hard to maintains the list(update, insert, delete, select)
fk column has maximum if as string
Solution build a intersection table. MySQL foreign key will automatically indexed and the fk should be reference another table index.
----------
Tree structure design
Don't use one child to one parent(self referencing) a.index a.parent reference a.index[adjacency list]
Hard to maintains(remove subtree need find the leaves first)
TBC(need deep study the example if have time)
1.Recursion query With clause(check mysql support or not)
2.Path variable a column set parent/parent/
(same problem as jaywalking)
3. CLOSURE Table (intersection table easiest)
4. Nested set(left node right node; real building C++ B-Tree)
同連登你幾層有咩reply有啲似
nornalization
nornalization
巴打過到screening? 唔係related background好難搵 
DB design logical antipattern 主要都係refactor一個intersection table就可以ko
略睇完SQL antipattern揾唔到我要既嘢，最多interview吹水用
重睇寫book summary好無不過無hands on experience => 無deep memory => 曬氣
開下本講attitude先
重睇寫book summary好無不過無hands on experience => 無deep memory => 曬氣開下本講attitude先
講下上份係乜公司乜post
me開頭三個月一樣，做多個零月習慣了
2023
唔夠好姐
