How do I access deep nested JSON data with go?

Original from Https://hashnode.com/post/how ...

In most cases, developers need to use and query JSON data from other services. Querying JSON documents is time consuming. In the past few days, I was writing a package for Golang to easily query JSON data. This idea and inspiration comes from Nahid Bin Azhar's Php-jsonq.

Let's look at a sample JSON data:

{   "name":"computers",   "description":"List of computer products",   "vendor":{      "name":"Star Trek",      "email":"info@example.com",      "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     ]   }}

Let's find a deep nested property and handle the error correctly, in which case we will try <font color= "Red" >name</font> from <font color= "Red" >items</ The second element of the font> array is accessed, note: <font color=red>items</font> is <font color= "Red" >vendor</font> The properties of the object.
See the following example:

package mainimport (    "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.Errors())    }    fmt.Println(res)}

Yahooooo! Very simple, huh? It looks like using Ormjson data. Let's look at some more examples to query the sample data.

Example 1

Enquiry: <font Color=red>select * from Vendor.items where price > or ID null</font>

Using Gojsonq we can execute the following query:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./sample-data.json")    res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).Get()    fmt.Println(res)    // output: [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: <font color=red> select name, price from Vendor.items where price > or ID null</font>

Using Gojsonq we can execute the following query:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./sample-data.json")    res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).Only("name", "price")    fmt.Println(res)    // output: [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: <font color=red> Select SUM (Price) from Vendor.items where price > or ID null</font>

Using Gojsonq we can execute the following query:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./sample-data.json")    res := jq.From("vendor.items").Where("price", ">", 1200).OrWhere("id", "=", nil).Sum("price")    fmt.Println(res)    // output: 3900}

Example 4

Enquiry: <font color=red>select price from Vendor.items where price > 1200</font>

Using Gojsonq we can execute the following query:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./sample-data.json")    res := jq.From("vendor.items").Where("price", ">", 1200).Pluck("price")    fmt.Println(res)    // output: [1350 1700]}

Example 5

Enquiry: <font color=red> SELECT * from Vendor.items ORDER by price</font>

Using Gojsonq we can execute the following query:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./sample-data.json")    res := jq.From("vendor.items").SortBy("price").Get()    fmt.Println(res)    // output: [map[id:<nil> name:HP core i3 SSD price:850] map[id:4 name:Fujitsu price:850] map[id:5 name:HP core i5 price:850 key:2300] map[id:6 name:HP core i7 price:950] map[id:3 name:Sony VAIO price:1200] map[id:1 name:MacBook Pro 13 inch retina price:1350] map[id:2 name:MacBook Pro 15 inch retina price:1700]]}

Example 6

With Gojsonq you can handle errors correctly, see the following code snippet:

package mainimport (    "log"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./invalid-file.xjsn")    err := jq.Error()    if err != nil {        log.Fatal(err)        // 2018/06/25 00:48:58 gojsonq: open ./invalid-file.xjsn: no such file or directory        // exit status 1    }}

Example 7

Let's say we have a JSON document like this

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

We want to run a query like this:

Query: <font color=red> SELECT * from Users where name.first=john</font>

This package makes it easy to query, see the following code snippet:

package mainimport (    "fmt"    "github.com/thedevsaddam/gojsonq")func main() {    jq := gojsonq.New().File("./data.json")    res := jq.From("users").WhereEqual("name.first", "John").Get()    fmt.Println(res) //output: [map[id:1 name:map[first:John last:Ramboo]] map[id:3 name:map[first:John last:Doe]]]}

You can use dot (. ) to access nested level properties, such as <font Color=red>where/groupby/sortby etc</font>

Note: There are other useful ways to make life easier! If you like the package, don't forget to share it with your community and star the repository