英文:
Returning results form a database query without using Scan - Golang
问题
根据我所了解，在Go语言中从数据库中获取数据的一般方式是像这里描述的那样：http://go-database-sql.org/retrieving.html
大致上可以这样做：
rows, err := db.Query("select id, name from users where id = ?", 1)
if err != nil {
log.Fatal(err)
}
defer rows.Close()
for rows.Next() {
err := rows.Scan(&id, &name)
if err != nil {
log.Fatal(err)
}
log.Println(id, name)
}
然而，如果我想为数据库访问创建一个包装器，我将无法在其中使用Scan，并且我也不想返回rows来处理。除了Scan之外，是否有任何方法可以获取从rows返回的对象？它们可能都是interface{}类型，但这完全可以接受。如果我遍历rows，是否有办法访问对象，以便我可以将其转换为给定的结构体或其他类型？
英文:
From what I can gather, in Go the way to fetch data from a database is generally something like described here: http://go-database-sql.org/retrieving.html
Doing something along the lines of :
rows, err := db.Query("select id, name from users where id = ?", 1)
if err != nil {
log.Fatal(err)
}
defer rows.Close()
for rows.Next() {
err := rows.Scan(&id, &name)
if err != nil {
log.Fatal(err)
}
log.Println(id, name)
}
If i wanted to create a wrapper for database access though I wouldnt be able to do the Scan in there and i would rather not return the rows to do that with. Is there any way to get the objects returned from the rows other than Scan? They would all be interface{}'s probably but thats totally fine. Failing that, if I iterate through the rows is there a way to get access ot the object so I could cast to a given struct or anything?
答案1
得分: 1
> 除了Scan之外，有没有其他方法可以获取从行返回的对象？
没有。
> 如果我遍历行，有没有办法访问对象，以便我可以将其转换为给定的结构或其他内容？
没有，不像你想象的那样（例如，Go中没有类型转换）。
将它们扫描到适合你需求的任何类型中，从interface{}到sql.RawBytes或实现Scanner接口的其他类型。请参考database/sql包的文档，特别是database/sql.Rows.Scan (https://pkg.go.dev/database/sql#Rows.Scan)。大多数情况下，查看文档会更快。
英文:
> Is there any way to get the objects returned from the rows other than Scan?
No.
> if I iterate through the rows is there a way to get access ot the object so I could cast to a given struct or anything?
No, not in they way you imagine (e.g. there are no casts in Go).
Scan them into whatever fits your needs, from interface{} to sql.RawBytes or smth implementing Scanner. Please consult the documentation of package database/sql, especially database/sql.Rows.Scan (https://pkg.go.dev/database/sql#Rows.Scan) . Most of the time it's quicker to look at the documentation.
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