意外类型，期望名称

Question

我尝试使用 golang。我是这个 golang 的新手。当我尝试连接到 mysql 时，我遇到了这样的错误：

./testCONnection.go:9:35: 语法错误：意外类型，预期名称 ./testCONnection.go:15:1：语法错误：函数体外的非声明语句 ./testCONnection.go:36:5: 语法错误：函数体外的非声明语句

我已经使用 root 运行了。

这里是我的源代码

主包

import "database/sql"
import "fmt"
import _"github.com/go-sql-driver/mysql"

type trade_history struct {
    id, final_meta_report_id, trading_account_id, lp, lp2, lp3             int
    symbol, price, price_type, time, type, status, created_at, updated_at  string
    qty, pegged_distance, price_limit                      double
}
var db *sql.DB
var err error

funct getTradingHistory (final_Meta_report_ID int) (err error){
    username := "lalala"
    password := "felixsiong"
    host := "trades.xawrs2.us-east-2.rds.amazonaws.com"
    port := 3306
    db := "trading_dashboard"

    //use Sprintf if you wanna parse a string with values
    conn := fmt.Sprintf("%s:%s@%s:%s/%s", username, password, host, port, db)
    db, err = sql.Open("mysql", conn)
    defer db.Close()
    if err != nil {
        fmt.Println(err.Error())
    }
    err = db.Ping()
    if err != nil {
        fmt.Println(err.Error())
    }
    var p trade_history

    //if you have multiple lines of texts use ` instead of "
    err = db.QueryRow(`select id, final_meta_report_id, 
    trading_account_id, symbol, qty, price, price_type, time, lp, 
    lp2, lp3, pegged_distance, price_limit, time_limit, type, status, created_at`).Scan(&p)
    if err != nil {
        fmt.Println(err.Error())
    }


    fmt.Printf("id: %d\n Final_meta_report_id: %d\n trading_account_id: %d\n symbol: %s\n qty: %.2f\n price: %s\n price_type: %s\n time: %s\n lp: %d\n lp2: %d\n lp3: %d\n pegged_distance: %.2f\n")

    return err
}

func main() {
    getTradingHistory(2074)
}

我已将我的代码更新为这个

package main

import (
    "database/sql"
    "fmt"

    _ "github.com/go-sql-driver/mysql"
)

var db *sql.DB
var err error

type trade_history struct {
    id, final_meta_report_id, trading_account_id, lp, lp2, lp3             int
    symbol, price, price_type, time, types, status, created_at, updated_at string
    qty, pegged_distance, price_limit                                      float64
}

func getTradingHistory(final_Meta_report_ID int) error {
    username := "lalala"
        password := "felixsiong"
        host := "trades.xawrs2.us-east-2.rds.amazonaws.com"
        port := 3306
        db := "trading_dashboard"

    //use Sprintf if you wanna parse a string with values
    conn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", username, password, host, port, db)
    //conn := fmt.Sprintf("%s:%s@%s:%s/%s", username, password, host, port, db)
    db, err = sql.Open("mysql", conn)
    defer db.Close()
    if err != nil {
        fmt.Println(err.Error())
    }
    err = db.Ping()
    if err != nil {
        fmt.Println(err.Error())
    }
    var p trade_history

    //if you have multiple lines of texts use ` instead of "
    err := db.QueryRow("select id, final_meta_report_id, 
    trading_account_id, symbol, qty, price, price_type, time, lp, 
    lp2, lp3, pegged_distance, price_limit, time_limit, type, status, created_at From trade_history Where final_Meta_report_ID = ?", final_Meta_report_ID ).Scan(&p)
    if err != nil {
        fmt.Println(err.Error())
    }

    fmt.Printf("id: %d\n Final_meta_report_id: %d\n trading_account_id: %d\n symbol: %s\n qty: %.2f\n price: %s\n price_type: %s\n time: %s\n lp: %d\n lp2: %d\n lp3: %d\n pegged_distance: %.2f\n")

    return err
}

func main() {
    getTradingHistory(2074)
}

但如果我使用终端运行，我仍然会遇到这样的错误

./testCOnnection.go:41:55: newline in string
./testCOnnection.go:41:55: syntax error: unexpected newline, expecting comma or )
./testCOnnection.go:43:57: syntax error: unexpected type at end of statement
./testCOnnec

tion.go:43:109: 无效字符 U+003F '?' ./testCONnection.go:43:144: 字符串中的换行符

如果我使用 Visual Studio 代码运行，我会遇到这样的错误

myConnectionMySql.go:5:8：在以下任何一个中都找不到包“github.com/go-sql-driver/mysql”： /usr/local/go/src/github.com/go-sql-driver/mysql（来自 $GOROOT） /Users/fuad/go/src/github.com/go-sql-driver/mysql（来自 $GOPATH） 退出状态 1

进程退出代码：1我的问题是如何解决我的问题？

Answer 1

我已经重写了你的代码：

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
)

var myDB *sql.DB
var err error

type trade_history struct {
    id, final_meta_report_id, trading_account_id, lp, lp2, lp3             int
    symbol, price, price_type, time, types, status, created_at, updated_at string
    qty, pegged_distance, price_limit                                      float64
}

func getTradingHistory(final_Meta_report_ID int) error {
    username := "lalala"
    password := "felixsiong"
    host := "trades.xawrs2.us-east-2.rds.amazonaws.com"
    port := 3306
    db := "trading_dashboard"

    //use Sprintf if you wanna parse a string with values
    conn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", username, password, host, port, db)
    myDB, err = sql.Open("mysql", conn)
    defer myDB.Close()
    if err != nil {
        fmt.Println(err.Error())
    }
    err = myDB.Ping()
    if err != nil {
        fmt.Println(err.Error())
    }

    var p trade_history

    //if you have multiple lines of texts use ` instead of "
    err = myDB.QueryRow(`select id, final_meta_report_id,
    trading_account_id, symbol, qty, price, price_type, time, lp,
    lp2, lp3, pegged_distance, price_limit, time_limit, type, status, created_at`).Scan(&p)
    if err != nil {
        fmt.Println(err.Error())
    }

    fmt.Println("id: %d\n Final_meta_report_id: %d\n trading_account_id: %d\n symbol: %s\n qty: %.2f\n price: %s\n price_type: %s\n time: %s\n lp: %d\n lp2: %d\n lp3: %d\n pegged_distance: %.2f\n")

    return err
}

func main() {
    if getTradingHistory(2074) != nil {
        fmt.Println(err.Error())
    }
}

有很多问题：

• type 是 go 的关键字
• funct 必须是 func
• myDB.QueryRow(....).Scan(&p) 需要重写。您可以找到正确的示例表单here
• fmt.Println("id: %d\n Final_meta_report_id:....... 需要以正确的方式为go 重写它
• double 将替换为 float32/float64

Answer 2

错误syntax error: unexpected type, expecting name 是关于在指定行号使用保留关键字type 作为变量名。关键字type是用来在golang中创建新类型的，不能用它作为变量名。

并且声明函数时有类型。它应该是func 而不是funct。剩下的两个错误都是关于这个的。

Answer 3

funct getTradingHistory

应该改成

func getTradingHistory 

Answer 4

改变这个：

funct getTradingHistory (final_Meta_report_ID int) (err error){}

到：

func getTradingHistory (final_Meta_report_ID int) (err error){}