英文:
Sorting in Go lang Interface
问题
我正在使用Go语言。我有一个动态数据创建的需求，所以我使用了一个接口来添加我的数据。
hives := make([]map[string]interface{}, lenHive)
在这个接口中，我添加了一些数据，并且其中一些数据是动态添加的。
在这个接口中，我有以下数据：
[
{
"Career-Business Owner": 0,
"Career-Entry-level": 0,
"Dependents-School age children (5-18)": 0,
"date created": "2021-10-22T13:44:32.655Z",
"date created": "2021-11-04T05:03:53.805Z",
"hive_id": 114,
"name": "Rule test1122-Hive 38",
"users": 3
},
{
"Career-Business Owner": 0,
"Career-Entry-level": 0,
"Dependents-School age children (5-18)": 0,
"date created": "2021-10-22T13:44:32.655Z",
"hive_id": 65,
"name": "Rule hive44555-Hive 8",
"users": 0
}
]
现在，我需要按照每个字段对这些数据进行排序（需要在每个字段上进行排序）。
我应该如何对接口中的字段进行排序？
这里的SortBy是字段（例如Career-Business Owner、Career-Entry-level、date created、hive_id、name、users）。
if SortBy != "" {
if SortOrder == "desc" {
sort.Slice(hives, func(i, j int) bool {
return hives[i][gpi.SortBy] == hives[j][gpi.SortBy]
})
} else {
sort.Slice(hives, func(i, j int) bool {
return hives[i][gpi.SortBy] != hives[j][gpi.SortBy]
})
}
}
但是排序没有正常工作。有没有对接口进行排序的方法？
或者是否存在其他解决这个问题的替代方法？
英文:
I am using Go. I have a dynamic data creation so I used an interface for adding my data.
hives := make([]map[string]interface{}, lenHive)
after some operation in this interface I added some data. In this interface some of the data are dynamically adding.
In this interface I have a data like below
[
{
"Career-Business Owner": 0,
"Career-Entry-level": 0,
"Dependents-School age children (5-18)": 0,
"date created": "2021-10-22T13:44:32.655Z",
"date created": "2021-11-04T05:03:53.805Z",
"hive_id": 114,
"name": "Rule test1122-Hive 38",
"users": 3
},
{
"Career-Business Owner": 0,
"Career-Entry-level": 0,
"Dependents-School age children (5-18)": 0,
"date created": "2021-10-22T13:44:32.655Z",
"hive_id": 65,
"name": "Rule hive44555-Hive 8",
"users": 0
}
]
now I need to sort this data with each field (need to use sorting in each field)
How can I sort filed from interface
here SortBy is the field (eg Career-Business Owner,Career-Entry-level,date created, hive_id,name,users)
if SortBy != "" {
if SortOrder == "desc" {
sort.Slice(hives, func(i, j int) bool {
return hives[i][gpi.SortBy] == hives[j][gpi.SortBy]
})
} else {
sort.Slice(hives, func(i, j int) bool {
return hives[i][gpi.SortBy] != hives[j][gpi.SortBy]
})
}
}
but the sorting is not working properly. What is the method for sorting interface ?
Or any alternative method exist for solving this?
答案1
得分: 2
你需要提供给sort.Slice的func应该在索引i处的值小于索引j处的值时返回true。因此，你应该用<替换==和!=，或者用>=进行逆向排序。
Go语言没有隐式类型转换，所以在你的less函数中，你需要使用类似type switch的方式检查每个字段的类型，并根据找到的类型进行比较。
例如：
sort.Slice(hives, func(i, j int) bool {
aInt := hives[i][gpi.SortBy]
bInt := hives[j][gpi.SortBy]
switch a := aInt.(type) {
case int:
if b, ok := bInt.(int); ok {
return a < b
}
panic("无法比较不同类型")
case string:
if b, ok := bInt.(string); ok {
return a < b
}
panic("无法比较不同类型")
default:
panic("未知类型")
}
})
英文:
The func you need to supply to sort.Slice should return true if the value at index i is less then the value at index i. So you should replace == and != with <, or with >= for reverse sorting.
Go has no implicit type casing so in your less func you will have to check the type of each field with something like a type switch and handle the comparison based on the type you find.
For example:
sort.Slice(hives, func(i, j int) bool {
aInt := hives[i][gpi.SortBy]
bInt := hives[j][gpi.SortBy]
switch a := aInt(type) {
case int:
if b, ok := bInt.(int); ok {
return a < b
}
panic("can't compare dissimilar types")
case string:
if b, ok := bInt.(string); ok {
return a < b
}
panic("can't compare dissimilar types")
default:
panic("unknown type")
}
})
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