工作筆記: dz-03 7, 8月 壓縮在壓縮~

SQL

---

Postgres insert date

• current_timestamp
  • 在時間內加時間
    • current_timestamp + interval ‘1 day’
  • ex:

       insert into table (create_time, estimated_time)
       value (current_timestamp, current_timestamp + interval '1 day')
  

sql 查看 time different

• http://www.sqlines.com/postgresql/how-to/datediff

	SQL Server and Sybase	PostgreSQL
Years	DATEDIFF(yy, start, end)	DATE_PART(‘year’, end) - DATE_PART(‘year’, start)
Months	DATEDIFF(mm, start, end)	years_diff * 12 + (DATE_PART(‘month’, end) - DATE_PART(‘month’, start))
Days	DATEDIFF(dd, start, end)	DATE_PART(‘day’, end - start)
Weeks	DATEDIFF(wk, start, end)	TRUNC(DATE_PART(‘day’, end - start)/7)
Hours	DATEDIFF(hh, start, end)	days_diff * 24 + DATE_PART(‘hour’, end - start )
Minutes	DATEDIFF(mi, start, end)	hours_diff * 60 + DATE_PART(‘minute’, end - start )
Seconds	DATEDIFF(ss, start, end)	minutes_diff * 60 + DATE_PART(‘minute’, end - start )

postgres get time with NOW()

select * from table t 
where t.start_time between ( NOW() - interval '50 day' ) and NOW ();

Sql 找重複 item

select t.item
from table t 
group by t.item
having count(*) > 1;

Go

---

Check string in []string

• sort

input := []string{"bird", "apple", "ocean", "fork", "anchor"}
sort.Strings(input)

fmt.Println(contains(input, "apple")) // true
fmt.Println(contains(input, "grow"))  // false

...

func contains(s []string, searchterm string) bool {
    i := sort.SearchStrings(s, searchterm)
    return i < len(s) && s[i] == searchterm
}

Time Caculation

// Common durations. There is no definition for units of Day or larger
// to avoid confusion across daylight savings time zone transitions.
//
// To count the number of units in a Duration, divide:
//	second := time.Second
//	fmt.Print(int64(second/time.Millisecond)) // prints 1000
//
// To convert an integer number of units to a Duration, multiply:
//	seconds := 10
//	fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
//
const (
	Nanosecond  Duration = 1
	Microsecond          = 1000 * Nanosecond
	Millisecond          = 1000 * Microsecond
	Second               = 1000 * Millisecond
	Minute               = 60 * Second
	Hour                 = 60 * Minute
)

 endTime = startTime.Add(time.Duration( (value.StdTp + value.StdTs*value.Qty)*60)*time.Second)

Go 寶哥 考試

Go: Compiled Language

• Go 迴圈

    for {...}
  	
    for true {...}
  

• Go example

package main

import "fmt"

func main(){
result := sum(1, 2)
fmt.Println(result)
}

func sum(x, y int) (res int) {
  res = x, y
  return
}

--> 3

• Go 每支原始檔案 .go

  • 含有 package 宣告

• Go

    package main
  	
    import _ github.comlib/pq
  	
    import "fmt"
  

  • 執行該 package 的 init 方法

• Go Modules 最主要的用途為何

  • package 相依去中心化

• Go get

  • go get github.com/gorilla/mux@>v1.7.2

  • 找到的可能版本：v1.7.3

• Go 檢查程式碼是否有錯誤 (例如是否含有 unreachable code 等問題)

  • go vet

• Go 列出 fmt 使用方式

  • go help fmt

• Go 會列出什麼結果

    package main
  	
    import "fmt"
  	
    func main() {
    ch := make(chan int)
    ch <- 10
    i :=  <- ch
    fmt.Prinln(i)
    }
  

  • fatal error: all goroutlines are asleep - deadlock!

• Go 會列出什麼結果

    package main
  	
    import {
       "fmt"
       "time"
    }
  	
    func main(){
    ch := make(chan int)
    go func() {
    time.Sleep(1 * time.Second)
    ch <- 10
    }()
    i := <- ch
    fmt.Println(i)
    }
  

  • 10

• Go 結果

   package main
     
   import (
     "fmt"
   )
     
   func main() {
   i, j := 99, 99
   setWithPointer(&i)
   setWithValue(j)
   fmt.Println(i, j)
   }
     
   func setWithPinter(i *int){
      *i = 100
   }
     
   func setWithValue(i int){
      i = 100
   }
  

  • i = 100, j = 99

• Go 執行後的輸出順序

    package main
      
    import ( 
    "fmt" 
    )
      
    func main() {
    defer fmt.Print("defer 1, ")
    fmt.Print("hello, ")
    defer fmt.Print("defer 2, ")
    }
  

  • hello, defer 2, defer 1,

Go xorm showSql

// ShowSQL show SQL statement or not on logger if log level is great than INFO
func (engine *Engine) ShowSQL(show ...bool) {
	engine.logger.ShowSQL(show...)
	if len(show) == 0 {
		engine.showSQL = true
	} else {
		engine.showSQL = show[0]
	}
}

go 剪字元

• queryStr[:len(queryStr)-3]

• https://www.rosettacode.org/wiki/Substring/Top_and_tail#Go

Go xorm 自組合 query string

• builder.Eq
  • type Eq map[string]interface{}

builder.Eq()
	
err = session.Select(selectSql).
		Limit(limit, startIndex).
		Where(builder.Eq(queryStr)).
		Find(&modal)

Golang switch

func main() {
	fmt.Print("Go runs on ")
	switch os := runtime.GOOS; os {
	case "darwin":
		fmt.Println("OS X.")
	case "linux":
		fmt.Println("Linux.")
	default:
		// freebsd, openbsd,
		// plan9, windows...
		fmt.Printf("%s.\n", os)
	}
}

Go struct assign

• https://stackoverflow.com/questions/24809235/initialize-a-nested-struct

Docker

---

Docker Ignore

• .dockerignore

# dependencies
/node_modules
/.pnp
.pnp.js
.git
.ipynb_checkpoints/*
/notebooks/*
/unused/*
Dockerfile
.DS_Store
.gitignore
README.md
env.*
/devops/*

# To prevent storing dev/temporary container data
*.csv
/tmp/*

Docker toolbox

• 看 docker toolbox run 起來的 ip 位置
  • docker-machine ip

Git

---

• show git graph
  • git log –all –graph –decorate

Python

---

pandas read json file

import pandas as pd
from pandas.io.json import json_normalize
import json
import os

with open("./jobs.json", "rb") as json_data:
    data = json.load(json_data)

df = pd.DataFrame.from_dict(data, orient='index')

Javascript

---

Date add date

// Create new Date instance
var date = new Date()

// Add a day
date.setDate(date.getDate() + 1)

e2e cypress

• https://docs.cypress.io/guides/getting-started/writing-your-first-test.html#Add-a-test-file

• install

  • npm install cypress –save-dev

  • Opening Cypress

    • ./node_modules/.bin/cypress open

• css selector

  • Copy Css Selector