Golang Dynamic SQL查询在App Engine中

Question

我想在Golang中制作动态SQL，我似乎找不到正确的方法。

基本上，我只想做：

query := "SELECT id, email, something FROM User"
var paramValues []string
filterString := ""
if userParams.Name != "" {
    paramString += " WHERE id = ?"
    paramValues = append(paramValues, userParams.Name)
}
if userParams.UserID != "" {
    if len(paramString) > 0 {
        paramString += " AND"
    } else {
        paramString += " WHERE"
    }
    paramString += " email = ?"
    paramValues = append(paramValues, userParams.UserID)
}
stmtOut, err := db.Prepare(query + paramString)
err = stmtOut.QueryRow(paramValues).Scan(&id, &email, &something)

与在mysql和golang中构建动态查询有关

我一直找不到不允许SQL注入的坚实方法。我上述解决方案的问题是queryrow（）不将[]字符串作为参数。

我想保护SQL注入，因此fmt.sprintf并不能真正解决问题。

这样，我可以使用ID或电子邮件在用户上进行搜索，并且我还将使用此逻辑对具有更可搜索字段的不同对象使用。

我正在使用go-sql-driver/mysql

Answer 1

这是我可以在本地计算机上运行的东西（go1.8 linux/amd64和当前GO MySQL驱动程序1.3）。

证明了两种方式。

package main
import (
    "database/sql"
    "log"
    _ "github.com/go-sql-driver/mysql"
    "fmt"
)
// var db *sql.DB
// var err error
/*
Database Name/Schema : Test123
Table Name: test
Table Columns and types:
number INT (PRIMARY KEY)
cube INT
*/
func main() {
    //Username root, password root
    db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/Test123?charset=utf8")
    if err != nil {
        fmt.Println(err) // needs proper handling as per app requirement
        return
    }
    defer db.Close()
    err = db.Ping()
    if err != nil {
        fmt.Println(err) // needs proper handling as per app requirement
        return
    }
    //Prepared statement for inserting data
    stmtIns, err := db.Prepare("INSERT INTO test VALUES( ?, ? )") // ? = placeholders
    if err != nil {
        panic(err.Error()) // needs proper handling as per app requirement
    }
    defer stmtIns.Close()
    //Insert cubes of 1- 10 numbers
    for i := 1; i < 10; i++ {
        _, err = stmtIns.Exec(i, (i * i * i)) // Insert tuples (i, i^3)
        if err != nil {
            panic(err.Error()) // proper error handling instead of panic in your app
        }
    }
    num := 3
    // Select statement
    dataEntity := "cube"
    condition := "WHERE number=? AND cube > ?"
    finalStatement := "SELECT " + dataEntity + " FROM test " + condition
    cubeLowerLimit := 10
    var myCube int
    err = db.QueryRow(finalStatement, num, cubeLowerLimit).Scan(&myCube)
    switch {
    case err == sql.ErrNoRows:
        log.Printf("No row with this number %d", num)
    case err != nil:
        log.Fatal(err)
    default:
        fmt.Printf("Cube for %d is %dn", num, myCube)
    }
    var cubenum int
    // //Prepared statement for reading data
    stmtRead, err := db.Prepare(finalStatement)
    if err != nil {
        panic(err.Error()) // needs proper err handling
    }
    defer stmtRead.Close()
    // Query for cube of 5
    num = 5
    err = stmtRead.QueryRow(num, cubeLowerLimit).Scan(&cubenum)
    switch {
    case err == sql.ErrNoRows:
        log.Printf("No row with this number %d", num)
    case err != nil:
        log.Fatal(err)
    default:
        fmt.Printf("Cube number for %d is %dn", num, cubenum)
    }
}

如果您在后续时间运行它，则需要删除数据库中的行，以使插入不会造成恐慌（或或者更改插入行代码，以免它慌张）。我没有在Google App Engine上尝试过。希望这会有所帮助。