trouble shooting,memo

branch name is just the lastest hash of commi branch name is just the lastest hash of commit
In fact, this is the very definition of a branch name: a name like master simply stores the hash ID of the commit we want to call the latest for that branch. So given the A--B--C string of commits, we just add the name master, pointing to commit C:

To remember which branch we want Git to update, as well as which commit we have checked-out right now, Git has the special name HEAD

current branch
A--B--C--D <-- develop (HEAD), master
HEAD still names the current commit.
A detached HEAD just means that Git has made the name HEAD point directly to some commit instead of attaching it to a branch name

git merge

git checkout master

set HEAD to master

git merge develop

go backwards from master and develop, to find a shared base commit (祖先), called merge base
The merge base commit is determined entirely by the commit graph,
git diff baseCommint master => get change set 1
git diff basecommit develop => get change set 2
git combine the difference , use a new commit id to save the result ( merge commit )

cherry-pick

git diff somecommitId to get the change set
just put the change on current commit(branch)
but it maybe not works very well, git use cherry-pick-style merge, force the merge base commit to be the parent of the cherry-picked commit.
cherry-pick create a new commit to save the result.

       G--H--F'   <-- master (HEAD)
      /
...--D
      \
       E--F   <-- develop

 cherry-pick uses Git's merge machinery to do the change-combining, but leaves the graph unmerged, simply making a copy of some existing commit

git merge somecommitid(branch)
git merge -no-ff

2023/10/12

2023/10/12

golang, postgres, sqlx

postgres, golang , sqlx, placeholder, in

sql: where some_id = any(:some_name)

golang, sqlx:

" some_name" : pg.StringArray([]string )

2023/07/06

2023/07/06

golang

vscode ,gvm ,GOROOT

gvm install go19.2
gvm list
gvm use go19.2 --default

=>GOROOT、GOPATH　will be set by gvm automatically

vsCode　will use the go defined by $GOROOT

2023/06/26

2023/06/26

kotest, kotlin

kotest -

"someContainer " - {

"someTest" { }

}

- はContainerの意味であり、その中に、別のScopeが必要

ない場合は、実行されない。

2023/05/31

2023/05/31

mysql

mysql explain select

## explain select

- access_type: 
  - all(全件検索)/index(indexの全件検索)はfull-scanであり、要注意。
  - indexはallより良い。
- possible_keys: 使用可能なindex(primary-key is index)
- key: 実際使ったindex
- ref: indexのKeyと比較するcolumn
- patition: 使ったpatition. patationは何？大きなテーブルを分解すること
  - patitionは使えるかも！
  - 分解のtypeは：RANGE,LIST,HASH,KEY
- rows: 大体の件数を推測した結果
- filtered: 条件が効いて、次の層に行く件数の割合。小さい方が良い。

2023/05/26

2023/05/26

rails

rails,reek, rubocop, ignore alert

# :reek:警告名称

# rubocop:disable Style/LineLength, Style/StringLiterals

2023/05/26

rails

rails, router,url_helper

puts Rails.application.routes.named_routes.helper_names

2023/05/26

rails

rails,where or

def check
@spec = Hash.new
@spec = Spec.merge(Spec.where(a:1).or(Spec.where(b:0)))
.merge(Spec.where(c:0).or(Spec.where(d:0))).first
end

2023/05/17

2023/05/17

git

change git http to ssh

- git add ssh key
- ssh-keygen -t rsa
- update to github ssh key
- ssh -T git@github.com

- add to .ssh/config

Host github github.com HostName github.com IdentityFile ~/.ssh/id_git_rsa #ここに自分の鍵のファイル名 User git

ssh -T github

- change git repository from http to ssh

git remote -v

git remote set-url origin git@github.com:xx/xx.git

git remote -v