Learning Go — from zero to hero

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  go操作mysql

  Go

  package main import ( "database/sql" "fmt" _ "github.com/go-sql-driver/mysql" ) func main() { /* db host: localhost db port: 3306 db version: 10.3.7-MariaDB database: create database go; table: create table Person(`uid` int(10) not null auto_increment, `name` varchar(50), `age` int(1), `city` varchar(50), primary key(`uid`)) ; */ //connect to mysql/mariadb //username:password@protocol(address)/dbname?param=value //my database is:go db, err := sql.Open("mysql", "root:123456@tcp(localhost:3306)/go?charset=utf8") checkErr(err) //insert mysql stmt, err := db.Prepare("INSERT Person SET name=?,age=?,city=?") checkErr(err) res, err := stmt.Exec("李玲", 35, "上海市") checkErr(err) id, _ := res.LastInsertId() fmt.Println("最后插入id", id) //update stmt, err = db.Prepare("update Person set name=? where uid=?") checkErr(err) res, err = stmt.Exec("李璐", 1) checkErr(err) affect, err := res.RowsAffected() checkErr(err) fmt.Println("更新行数：", affect) //delete. stmt, err = db.Prepare("delete from Person where name=?") checkErr(err) res, err = stmt.Exec("李玲") checkErr(err) affect2, err2 := res.RowsAffected() checkErr(err2) fmt.Println("删除行数", affect2) //select mysql. rows, err := db.Query("SELECT * FROM Person") checkErr(err) for rows.Next() { var uid int var name string var age int var city string err = rows.Scan(&uid, &name, &age, &city) checkErr(err) fmt.Println(uid, name, age, city) } //关闭mysql数据库连接 db.Close() } func checkErr(err error) { if err != nil { //err非空则表明遇到错误. panic(err) } }

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  package main   import ( "database/sql" "fmt"   _ "github.com/go-sql-driver/mysql" )   func main() { /* db host: localhost db port: 3306 db version: 10.3.7-MariaDB   database: create database go; table: create table Person(`uid` int(10) not null auto_increment, `name` varchar(50), `age` int(1), `city` varchar(50), primary key(`uid`)) ; */   //connect to mysql/mariadb //username:password@protocol(address)/dbname?param=value //my database is:go db, err := sql.Open("mysql", "root:123456@tcp(localhost:3306)/go?charset=utf8") checkErr(err)   //insert mysql stmt, err := db.Prepare("INSERT Person SET name=?,age=?,city=?") checkErr(err)   res, err := stmt.Exec("李玲", 35, "上海市") checkErr(err)   id, _ := res.LastInsertId() fmt.Println("最后插入id", id)   //update stmt, err = db.Prepare("update Person set name=? where uid=?") checkErr(err)   res, err = stmt.Exec("李璐", 1) checkErr(err)   affect, err := res.RowsAffected() checkErr(err)   fmt.Println("更新行数：", affect)   //delete. stmt, err = db.Prepare("delete from Person where name=?") checkErr(err)   res, err = stmt.Exec("李玲") checkErr(err)   affect2, err2 := res.RowsAffected() checkErr(err2) fmt.Println("删除行数", affect2)   //select mysql. rows, err := db.Query("SELECT * FROM Person") checkErr(err)   for rows.Next() { var uid int var name string var age int var city string err = rows.Scan(&uid, &name, &age, &city) checkErr(err) fmt.Println(uid, name, age, city) }   //关闭mysql数据库连接 db.Close()   }   func checkErr(err error) { if err != nil { //err非空则表明遇到错误. panic(err) } }

   

  ag

  2018.06.08

  1.8K000
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  Go slice

  Go

  package main import ( "fmt" ) func main() { s1 := make([]int, 5, 8) s1[0] = 100 s1[1] = 100 s1[2] = 200 s1[3] = 888 s1[4] = 999 //a1 := [...]int{1, 3, 5, 7, 9} // s1 = a1[3:] //s1 = a1[1:4] s2 := make([]int, 8, 10) s2[3] = 699 s2[4] = 799 // copy(s2, s1) // copy(s1, s2) s2 = append(s2, 9, 10, 11, 12) fmt.Printf("%p,%v,%d,%d\n", s1, s1, len(s1), cap(s1)) fmt.Printf("%p,%v,%d,%d", s2, s2, len(s2), cap(s2)) }

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  package main   import ( "fmt" )   func main() { s1 := make([]int, 5, 8)   s1[0] = 100 s1[1] = 100 s1[2] = 200 s1[3] = 888 s1[4] = 999   //a1 := [...]int{1, 3, 5, 7, 9} // s1 = a1[3:] //s1 = a1[1:4]   s2 := make([]int, 8, 10) s2[3] = 699 s2[4] = 799   // copy(s2, s1) // copy(s1, s2) s2 = append(s2, 9, 10, 11, 12) fmt.Printf("%p,%v,%d,%d\n", s1, s1, len(s1), cap(s1)) fmt.Printf("%p,%v,%d,%d", s2, s2, len(s2), cap(s2))   }

   

  ag

  2018.01.23

  1.2K400
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  GO array

  Go

  package main import ( "fmt" ) func main() { // var stu [10]int // stu := [10]int{1, 2} // var stu [10]string // stu[0] = "GO_lang" // stu[5] = "C++" // stu := [...]int{5: 9008} // stu1 := [5]int{} // stu2 := [3]int{} // stu2 == stu1 // var stu = new([5]int) // stu := [...][3]string{ // {"zhangsan", "shenzhen", "luohu"}, // {"wangwu", "shenzhen", "futian"}, // } var stu [10]int for i := 0; i < 10; i++ { stu[i] = i * 3 } fmt.Println(stu) fmt.Println(&stu) }

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  package main   import ( "fmt" )   func main() { // var stu [10]int // stu := [10]int{1, 2}   // var stu [10]string // stu[0] = "GO_lang" // stu[5] = "C++"   // stu := [...]int{5: 9008}   // stu1 := [5]int{} // stu2 := [3]int{} // stu2 == stu1   // var stu = new([5]int)   // stu := [...][3]string{ // {"zhangsan", "shenzhen", "luohu"}, // {"wangwu", "shenzhen", "futian"}, // }   var stu [10]int   for i := 0; i < 10; i++ { stu[i] = i * 3 }   fmt.Println(stu) fmt.Println(&stu)   }

   

  ag

  2018.01.23

  1.3K000
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  Windows下使用go连接SAP RFC函数

  使用SAP的nwrfcsdk和gorfc库。 基本步骤如下：

  Shell

  Windows下使用go连接SAP RFC函数 #安装nwrfcsdk C:\nwrfcsdk #配置path ;C:\nwrfcsdk\lib #配置环境变量 变量名：CGO_CFLAGS 变量值：C:\nwrfcsdk\include 变量名：CGO_LDFLAGS 变量值：C:\nwrfcsdk\lib #安装gcc https://sourceforge.net/projects/mingw/ #安装go saprfc库 go get github.com/stretchr/testify go get github.com/sap/gorfc cd $GOPATH/src/github.com/sap/gorfc/gorfc go build go install #Hello World package main import ( "fmt" "github.com/sap/gorfc/gorfc" "github.com/stretchr/testify/assert" "reflect" "testing" "time" ) func abapSystem() gorfc.ConnectionParameter { return gorfc.ConnectionParameter{ Dest: "I64", Client: "800", User: "demo", Passwd: "welcome", Lang: "EN", Ashost: "11.111.11.111", Sysnr: "00", Saprouter: "/H/222.22.222.22/S/2222/W/xxxxx/H/222.22.222.222/H/", } } func main() { c, _ := gorfc.Connection(abapSystem()) var t *testing.T params := map[string]interface{}{ "IMPORTSTRUCT": map[string]interface{}{ "RFCFLOAT": 1.23456789, "RFCCHAR1": "A", "RFCCHAR2": "BC", "RFCCHAR4": "ÄBC", "RFCINT1": 0xfe, "RFCINT2": 0x7ffe, "RFCINT4": 999999999, "RFCHEX3": []byte{255, 254, 253}, "RFCTIME": time.Now(), "RFCDATE": time.Now(), "RFCDATA1": "HELLÖ SÄP", "RFCDATA2": "DATA222", }, } r, _ := c.Call("STFC_STRUCTURE", params) assert.NotNil(t, r["ECHOSTRUCT"]) importStruct := params["IMPORTSTRUCT"].(map[string]interface{}) echoStruct := r["ECHOSTRUCT"].(map[string]interface{}) assert.Equal(t, importStruct["RFCFLOAT"], echoStruct["RFCFLOAT"]) assert.Equal(t, importStruct["RFCCHAR1"], echoStruct["RFCCHAR1"]) assert.Equal(t, importStruct["RFCCHAR2"], echoStruct["RFCCHAR2"]) assert.Equal(t, importStruct["RFCCHAR4"], echoStruct["RFCCHAR4"]) assert.Equal(t, importStruct["RFCINT1"], echoStruct["RFCINT1"]) assert.Equal(t, importStruct["RFCINT2"], echoStruct["RFCINT2"]) assert.Equal(t, importStruct["RFCINT4"], echoStruct["RFCINT4"]) // assert.Equal(t, importStruct["RFCHEX3"], echoStruct["RFCHEX3"]) assert.Equal(t, importStruct["RFCTIME"].(time.Time).Format("150405"), echoStruct["RFCTIME"].(time.Time).Format("15. assert.Equal(t, importStruct["RFCDATE"].(time.Time).Format("20060102"), e/Users/d037732/Downloads/gorfc/README.mdchoStruct["RFCDATE"].(time.Time).Format(". assert.Equal(t, importStruct["RFCDATA1"], echoStruct["RFCDATA1"]) assert.Equal(t, importStruct["RFCDATA2"], echoStruct["RFCDATA2"]) fmt.Println(reflect.TypeOf(importStruct["RFCDATE"])) fmt.Println(reflect.TypeOf(importStruct["RFCTIME"])) c.Close()

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  Windows下使用go连接SAP RFC函数   #安装nwrfcsdk C:\nwrfcsdk   #配置path ;C:\nwrfcsdk\lib   #配置环境变量 变量名：CGO_CFLAGS   变量值：C:\nwrfcsdk\include 变量名：CGO_LDFLAGS  变量值：C:\nwrfcsdk\lib   #安装gcc https://sourceforge.net/projects/mingw/   #安装go saprfc库 go get github.com/stretchr/testify go get github.com/sap/gorfc cd $GOPATH/src/github.com/sap/gorfc/gorfc go build go install   #Hello World package main   import (     "fmt"     "github.com/sap/gorfc/gorfc"     "github.com/stretchr/testify/assert"     "reflect"     "testing"     "time" )   func abapSystem() gorfc.ConnectionParameter {     return gorfc.ConnectionParameter{         Dest:      "I64",         Client:    "800",         User:      "demo",         Passwd:    "welcome",         Lang:      "EN",         Ashost:    "11.111.11.111",         Sysnr:     "00",         Saprouter: "/H/222.22.222.22/S/2222/W/xxxxx/H/222.22.222.222/H/",     }   }   func main() {     c, _ := gorfc.Connection(abapSystem())     var t *testing.T       params := map[string]interface{}{         "IMPORTSTRUCT": map[string]interface{}{             "RFCFLOAT": 1.23456789,             "RFCCHAR1": "A",             "RFCCHAR2": "BC",             "RFCCHAR4": "ÄBC",             "RFCINT1":  0xfe,             "RFCINT2":  0x7ffe,             "RFCINT4":  999999999,             "RFCHEX3":  []byte{255, 254, 253},             "RFCTIME":  time.Now(),             "RFCDATE":  time.Now(),             "RFCDATA1": "HELLÖ SÄP",             "RFCDATA2": "DATA222",         },     }       r, _ := c.Call("STFC_STRUCTURE", params)       assert.NotNil(t, r["ECHOSTRUCT"])     importStruct := params["IMPORTSTRUCT"].(map[string]interface{})     echoStruct := r["ECHOSTRUCT"].(map[string]interface{})     assert.Equal(t, importStruct["RFCFLOAT"], echoStruct["RFCFLOAT"])     assert.Equal(t, importStruct["RFCCHAR1"], echoStruct["RFCCHAR1"])     assert.Equal(t, importStruct["RFCCHAR2"], echoStruct["RFCCHAR2"])     assert.Equal(t, importStruct["RFCCHAR4"], echoStruct["RFCCHAR4"])     assert.Equal(t, importStruct["RFCINT1"], echoStruct["RFCINT1"])     assert.Equal(t, importStruct["RFCINT2"], echoStruct["RFCINT2"])     assert.Equal(t, importStruct["RFCINT4"], echoStruct["RFCINT4"])     //  assert.Equal(t, importStruct["RFCHEX3"], echoStruct["RFCHEX3"])     assert.Equal(t, importStruct["RFCTIME"].(time.Time).Format("150405"), echoStruct["RFCTIME"].(time.Time).Format("15.     assert.Equal(t, importStruct["RFCDATE"].(time.Time).Format("20060102"), e/Users/d037732/Downloads/gorfc/README.mdchoStruct["RFCDATE"].(time.Time).Format(".     assert.Equal(t, importStruct["RFCDATA1"], echoStruct["RFCDATA1"])     assert.Equal(t, importStruct["RFCDATA2"], echoStruct["RFCDATA2"])       fmt.Println(reflect.TypeOf(importStruct["RFCDATE"]))     fmt.Println(reflect.TypeOf(importStruct["RFCTIME"]))       c.Close()

  ag

  2018.06.21

  5.3K1200
• 文章

  Linux下使用go语言连接SAP RFC函数的方式

  GO程序连接SAP RFC函数测试代码。 GO调用SAP RFC函数

  ag

  2018.06.29

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  使用sublime text开发GO应用

  使用sublime text开发GO应用 下载sublime text和GO运行环境 sublime text GO运行环境 如果打不开golang官网（需要能上google）请用…

  ag

  2018.01.24

  2.1K000
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  使用vscode做go开发

  1.先安装go运行环境，设置好GOPATH、GOROOT和GOBIN、PATH信息。 参考：GO语言学习环境搭建 2.安装gitscm 网址：https://git-scm.com…

  ag

  2018.01.25

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  Go实现九九乘法表

  Go

  package main import "fmt" func main() { var a rune var b rune for a = 1; a <= 9; a++ { for b = 1; b <= a; b++ { fmt.Printf("%d * %d = %2d\t", a, b, a*b) if b == a { println() } } } }

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  package main   import "fmt"   func main() { var a rune var b rune   for a = 1; a <= 9; a++ { for b = 1; b <= a; b++ { fmt.Printf("%d * %d = %2d\t", a, b, a*b) if b == a { println() } } } }

   

  ag

  2018.01.22

  1.3K100
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  GO语言学习环境搭建

  开发环境 操作系统：Fedora-Workstation-x86_64-27-1.6 Go版本：1.9.2 下载安装包：https://golang.org/dl/ 选择Linux…

  ag

  2018.01.22

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  Go语言热门应用

  Docker Codis Glow（类似于Hadoop） Cockroach（数据库） InfluxDB（时序数据库）等。

  ag

  2020.05.15

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