type Transaction struct{
     Id string `bson:"_id,omitempty"`
     TransId string 
}
func GetTransactionID() (id interface{}, err error){
    query := bson.M{}
    transId, err := dbEngine.Find("transactionId", WalletDB, query)
    //transId 是 []interface{} 类型
    id, err1 := transId.(Transaction)
    return transId, err
}
###Find 
package dbEngine 
func Find(collectionName,dbName string, query interface{})(result []interface{}, err error){
    collection := session.DB(dbName).C(collectionName)
    err = collection.Find(query).All(&result)
    return result, err
}
###Problem 
`Error:` invalid type assertion: transId.(string) (non-interface type []interface {} on left)
有没有建议将 `[]interface{}` 更改为 `Transaction` 类型的方法？
<details>
<summary>英文:</summary>
I am started working in `Go`. Having the following code 
     type Transaction struct{
          Id string `bson:&quot;_id,omitempty&quot;`
          TransId string 
     }
     func GetTransactionID() (id interface{}, err error){
	  query := bson.M{}
	  transId, err := dbEngine.Find(&quot;transactionId&quot;, WalletDB, query)
      //transId is []interface{} type
	  id, err1 := transId.(Transaction)
	  return transId, err
    }
###Find 
    package dbEngine 
    func Find(collectionName,dbName string, query interface{})(result []interface{}, err error){
	   collection := session.DB(dbName).C(collectionName)
	   err = collection.Find(query).All(&amp;result)
	   return result, err
    }
###Problem 
 `Error:` invalid type assertion: transId.(string) (non-interface type []interface {} on left)
Any suggestion to change the `[]interface{}` to `Transaction` type.
</details>
# 答案1
**得分**: 8
你不能将`interface{}`的切片转换为任何单个的结构体。你确定你真的不想要一个`Transaction`的切片（即`[]Transaction`类型）吗？如果是这样，你需要遍历它并逐个进行转换：
```go
for _, id := range transId {
    id.(Transaction) // 对这个进行操作
}