如何使用 Golang 在 SQL 中执行 IN 查找

发布于11月29日

Go希望这个SQL查询中的第二个参数是什么.

stmt, err := db.Prepare("SELECT * FROM awesome_table WHERE id= $1 AND other_field IN $2")
rows, err := stmt.Query(10, ???)

我真正想要的是:

SELECT * FROM awesome_table WHERE id=10 AND other_field IN (this, that);

推荐答案

查询只需要varargs来替换sql中的参数

rows, err := stmt.Query(10)

比如说，你的第二个例子的这个和那个都是动态的，那么你会这样做

stmt, err := db.Prepare("SELECT * FROM awesome_table WHERE id=$1 AND other_field IN ($2, $3)")
rows, err := stmt.Query(10,"this","that")

如果"IN"部分有变量args，则可以执行(play)

package main

import "fmt"
import "strings"

func main() {
    stuff := []interface{}{"this", "that", "otherthing"}
    sql := "select * from foo where id=? and name in (?" + strings.Repeat(",?", len(stuff)-1) + ")"
    fmt.Println("SQL:", sql)
    args := []interface{}{10}
    args = append(args, stuff...)
    fakeExec(args...)
    // This also works, but I think it's harder for folks to read
    //fakeExec(append([]interface{}{10},stuff...)...)
}

func fakeExec(args ...interface{}) {
    fmt.Println("Got:", args)
}