How to Define Multiple JSON and BSON Tags in a Go Struct?

Defining Multiple Field Tags in a Go Struct

To retrieve data from a MongoDB database and encode it for JSON, you need to define a struct with appropriate tags for both MongoDB and JSON serialization. However, you encounter an issue where your JSON-encoded fields are displaying in uppercase instead of the desired lowercase. To resolve this, you want to define multiple name tags within a field's tag string.

The solution to this challenge is to utilize space as the tag string separator instead of commas. The following updated code demonstrates this approach:

type Page struct {
    PageId string                 `bson:"pageId" json:"pageId"`
    Meta   map[string]interface{} `bson:"meta" json:"meta"`
}

According to the Go reflect package documentation, tag strings follow a specific convention:

"By convention, tag strings are a concatenation of optionally space-separated key:"value" pairs."

Adhering to this convention allows you to define multiple name tags for each field within a single tag string. The order of the name tags does not matter, and the values should be quoted using the " character.

The above is the detailed content of How to Define Multiple JSON and BSON Tags in a Go Struct?. For more information, please follow other related articles on the PHP Chinese website!