How to filter []struct with struct?

I define struct like this:

type Repo struct {
	Key         string `json:"key"`
	Type        string `json:"type"`
	PackageType string `json:"packageType"`
}

And json data is something like

> [
{
"key":"docker-sre",
"type":"LOCAL",
"packageType":"Docker"
},
{
"key":"docker-test",
"type":"REMOTE",
"packageType":"Docker"
},
{
"key":"go-local-dev",
"type":"LOCAL",
"packageType":"Go"
},
{
"key":"helm-cloudops",
"type":"LOCAL",
"packageType":"Helm"
}
]

What is the best way to get the correct data with different conditions?

func getWantedRepos(conf Repo) ([]Repo, error) {}

func main() {
    getWantedRepos(Repo{
		PackageType: "Docker",
	})

    getWantedRepos(Repo{
        Type: "LOCAL",
		PackageType: "Go",
	})
}

You can use reflect built-in package to do this. This is the example:

main.go

package main
import (
"fmt"
"reflect"
)
type Repo struct {
Key         string `json:"key"`
Type        string `json:"type"`
PackageType string `json:"packageType"`
}
var someDatas = []Repo{
{
Key:         "test",
Type:        "test",
PackageType: "test",
},
{
Key:         "test1",
Type:        "test1",
PackageType: "test1",
},
{
Key:         "test",
Type:        "LOCAL",
PackageType: "test23",
},
}
func getWantedRepos(conf map[string]interface{}) []Repo {
var returned []Repo
for _, val := range someDatas {
flag := true
for k := range conf {
if !reflect.DeepEqual(reflect.ValueOf(val).FieldByName(k).Interface(), conf[k]) {
flag = false
break
}
}
if flag {
returned = append(returned, val)
}
}
return returned
}
func main() {
var repos []Repo
repos = getWantedRepos(map[string]interface{}{
"Key": "test",
})
fmt.Println("1 ============================")
fmt.Printf("%+v\n", repos)
repos = getWantedRepos(map[string]interface{}{
"Type": "LOCAL",
})
fmt.Println("2 ============================")
fmt.Printf("%+v\n", repos)
repos = getWantedRepos(map[string]interface{}{
"Type":        "LOCAL",
"PackageType": "test23",
})
fmt.Println("3 ============================")
fmt.Printf("%+v\n", repos)
repos = getWantedRepos(map[string]interface{}{
"Type":        "LOCAL",
"PackageType": "NONE",
})
fmt.Println("4 ============================")
fmt.Printf("%+v\n", repos)
}

Output:

1 ============================
[{Key:test Type:test PackageType:test} {Key:test Type:LOCAL PackageType:test23}]
2 ============================
[{Key:test Type:LOCAL PackageType:test23}]
3 ============================
[{Key:test Type:LOCAL PackageType:test23}]
4 ============================
[]

I use map[string]interface{} instead of Model filtering because if you use a model, for example with string attribute, the default value of string is "". Even if you didn't initialize the value of the attribute, it will have "" as the default value, and the reflect for loop will scan through and try to match model with empty string "", so to avoid that, I use map[string]interface so we are more flexible to select attribute we want and vise versa.

I don't know what test case you have, but if you get the datas from database, try to use the WHERE instead of doing it like this.