golang中用于连接mysql的无效字符

Question

我是使用 golang 的新手并尝试连接到 mySql

这是我的源代码。当我运行这个示例代码时，我得到了错误。错误详细信息在源代码下方

package main

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){

        db, err = sql.Open("mysql", username:[e-mail]:3306/trading_dashboard

        defer db.Close()

        if err != nil {

                fmt.Println(err.Error())

        }

        err = db.Ping()

        if err != nil{

        fmt.Println(err.Error())

        }

        var p trade_history

        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, u$

        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 pr$

        return err

}

func main(){

        getTradingHistory(2074)

}

我遇到了这样的错误

# command-line-arguments

./myConnectionMySql.go:9:35: syntax error: unexpected type, expecting name

./myConnectionMySql.go:15:1: syntax error: non-declaration statement outside function body

./myConnectionMySql.go:16:56: invalid character U+0040 '@'

./myConnectionMySql.go:26:2: syntax error: non-declaration statement outside function body

./myConnectionMySql.go:30: newline in string

如何解决这个问题？

Answer 1

这样做，代码对它们有注释，您可以阅读并适应您的需求。package mainimport "database/sql"import "fmt"import _ "github.com/go-sql-driver/mysql"type trade_history struct {    // best practice in golang is to name your field in upper camel case if you intend to export it    // or lower camel case if you don't.    id, final_meta_report_id, trading_account_id, lp, lp2, lp3 int    // `type` is reserved keyword, therefore for example, i use `ptype`    symbol, price, price_type, time, ptype, status, created_at, updated_at string    qty, pegged_distance, price_limit                                      double}// you don't need to declare global variable like this, if you want it to be accessible to all your packages// it's best to use struct.// var db *sql.DB// var err error -- this one is shadowed by declaration of err in your getTradingHistory anyway.func getTradingHistory(reportId int) (err error) {    // Your dsn is unquoted hence error    db, err := sql.Open("mysql", "username:[e-mail]:3306/trading_dashboard")    // your trade data is here    defer db.Close()    if err != nil {        fmt.Println(err.Error())    }    err = db.Ping()    if err != nil {        fmt.Println(err.Error())    }    var th trade_history    // this one is also unquoted and your SQL statement is not correct    // here i add `FROM [YOUR TABLE] that you can edit to your needs`    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 [YOUR TABLE] WHERE id = ?", reportId).Scan( /* Scan your fields here */ ) // This is where you should scan your fields.    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 pr$")    return err}func main() {    getTradingHistory(2074)}

Answer 2

您应该修复错误，查看代码注释如下：package mainimport "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, typeField, status, created_at, updated_at string    qty, pegged_distance, price_limit                                          double}var db *sql.DBvar err errorfunc getTradingHistory(final_Meta_report_ID int) (err error) {    host := "trade.asdewx134.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)}