在Golang中从MySql读取Json数据？

Question

I am facing a case where I had to store dynamic values in the database with key and value pairs given by the user itself.

User gives the key and value, and I interpret it as

{"key": "user Given", "value": "user Given"}

and I add all such things to an array, and I want this array to be read into Go code where the array of objects is read from the Database table.

Answer 1

A quick hack, not necessarily the most elegant approach, is to use Golang's default JSON Unmarshaler behavior for golang maps:

jstr := `{"key": "userKeyValue", "value": "userValueValue"}`

// declare a map that has a key string and value interface{} so that any values or
// types will be accepted;
jmap := make(map[string]interface{})

err := json.Unmarshal(jstr, &jmap)
if err != nil {
    log.Fatal(err)
}

for k, v := range jmap {
    fmt.Printf("Key: %v, Value: %v
", k, v)
    // If you want to directly work with v remember it is an interface{}
    // Thus to use it as a string you must v.(string)
}
// Will output the following:
// Key: key, Value: userKeyValue
// Key: value, Value: userValueValue

You can now use standard golang map to manipulate or manage the received data... The more elegant approach is to implement the JSON Marshaler and Unmarshaler interfaces for your declared type. These are described in the golang documentation: https://golang.org/pkg/encoding/json/