使用Go语言访问JSON数据(gojsonq)

主要是使用第三方的库 gojsonq,来查询JSON数据

例如这样的JSON数据

{
 "name":"computers",
 "description":"List of computer products",
 "vendor":{
 "name":"Star Trek",
 "email":"[email protected]",
 "website":"www.example.com",
 "items":[
 {
 "id":1,
 "name":"MacBook Pro 13 inch retina",
 "price":1350
 },
 {
 "id":2,
 "name":"MacBook Pro 15 inch retina",
 "price":1700
 },
 {
 "id":3,
 "name":"Sony VAIO",
 "price":1200
 },
 {
 "id":4,
 "name":"Fujitsu",
 "price":850
 },
 {
 "id":5,
 "name":"HP core i5",
 "price":850,
 "key":2300
 },
 {
 "id":6,
 "name":"HP core i7",
 "price":950
 },
 {
 "id":null,
 "name":"HP core i3 SSD",
 "price":850
 }
 ],
 "prices":[
 2400,
 2100,
 1200,
 400.87,
 89.90,
 150.10
 ],
 "names":[
 "John Doe",
 "Jane Doe",
 "Tom",
 "Jerry",
 "Nicolas",
 "Abby"
 ]
 }
}

安装导入 gojsonq

go get github.com/thedevsaddam/gojsonq
or
go get gopkg.in/thedevsaddam/gojsonq.v1

引入

import "github.com/thedevsaddam/gojsonq"
or 
import "gopkg.in/thedevsaddam/gojsonq.v1"

可以像ORM访问数据库一样，访问JSON数据

简单应用

package main
import (
 "fmt"
 "log"
 "github.com/thedevsaddam/gojsonq"
)
func main() {
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.Find("vendor.items.[1].name")
 if jq.Error() != nil {
 log.Fatal(jq.Error())
 }
 fmt.Println(res)
}

输出结果

MacBook Pro 15 inch retina

Example 1

Query select * from vendor.items where price > 1200 or id null

使用 gojsonq 的方式查询

func ex1(){
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).Get()
 fmt.Println(res)
}

输出结果

[map[price:1350 id:1 name:MacBook Pro 13 inch retina] map[id:2 name:MacBook Pro 15 inch retina price:1700] map[id:<nil> name:HP core i3 SSD price:850]]

Example 2

Query select name,price from vendor.items where price > 1200 or id null

使用 gojsonq 的方式查询

func ex2() {
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).
 Only("name", "price")
 fmt.Println(res)
}

输出结果

[map[name:MacBook Pro 13 inch retina price:1350] map[name:MacBook Pro 15 inch retina price:1700] map[name:HP core i3 SSD price:850]]

Example 3

Query select sum(price) from vendor.items where price > 1200 or id null

使用 gojsonq 的方式查询

func ex3() {
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).Sum("price")
 fmt.Println(res)
}

输出结果

3900

Example 4

Query select price from vendor.items where price > 1200

使用 gojsonq 的方式查询

func ex4() {
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.From("vendor.items").Where("price", ">", 1200).Pluck("price")
 fmt.Println(res)
}

输出结果

[1350 1700]

Example 5

Query select * from vendor.items order by price

使用 gojsonq 的方式查询

func ex5() {
 jq := gojsonq.New().File("./sample-data.json")
 res := jq.From("vendor.items").SortBy("price").Get()
 fmt.Println(res)
}

输出结果

[map[id:<nil> name:HP core i3 SSD price:850] map[id:4 name:Fujitsu price:850] map[price:850 key:2300 id:5 name:HP core i5] map[id:6 name:HP core i7 price:950] map[name:Sony VAIO price:1200 id:3] map[id:1 name:MacBook Pro 13 inch retina price:1350] map[price:1700 id:2 name:MacBook Pro 15 inch retina]]

Example 6

处理相关的错误信息

func ex6() {
 jq := gojsonq.New().File("./sample-data.txt")
 err := jq.Error()
 if err != nil {
 log.Fatalln(err)
 }
}

输出结果

2018/09/27 11:20:42 gojsonq: open ./sample-data.txt: The system cannot find the file specified.

Example 7

如这样的JSON数据

{
 "users":[
 {
 "id":1,
 "name":{
 "first":"John",
 "last":"Ramboo"
 }
 },
 {
 "id":2,
 "name":{
 "first":"Ethan",
 "last":"Hunt"
 }
 },
 {
 "id":3,
 "name":{
 "first":"John",
 "last":"Doe"
 }
 }
 ]
}

实现这样的查询 select * from users where name.first=John

使用 gojsonq 的方式查询

func ex7() {
 jq := gojsonq.New().File("./data.json")
 res := jq.From("users").WhereEqual("name.first", "John").Get()
 fmt.Println(res)
}

输出结果

[map[id:1 name:map[first:John last:Ramboo]] map[id:3 name:map[first:John last:Doe]]]