[N] JSONdB model for kafka<->GORM

datamodels.go

@@ -0,0 +1,68 @@
+// For furture references related to this:
+// https://coussej.github.io/2016/02/16/Handling-JSONB-in-Go-Structs/
+// https://github.com/jinzhu/gorm/issues/1155
+
+package datamodels
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"errors"
+)
+
+// JSONdb type
+//
+// This type is meant to be used when the double interaction between GORM and
+// JSON (un)marshalling is needed
+type JSONdb map[string]interface{}
+
+// Value method for the interface.
+//
+// To satisfy this interface, we must implement the Value method, which
+// must transform our type to a database driver compatible type.
+// In our case, we’ll marshall the map to JSONB data (= []byte):
+func (j JSONdb) Value() (driver.Value, error) {
+
+	m, e := json.Marshal(j)
+
+	return m, e
+
+}
+
+// Scan method for the interface.
+//
+// This method must take the raw data that comes from the database
+// and transform it to our new type. In our case, the database will
+// return JSONB ([]byte) that we must transform to our type
+// (the reverse of what we did with driver.Valuer):
+func (p *JSONdb) Scan(src interface{}) error {
+
+	source, ok := src.([]byte)
+
+	if !ok {
+
+		return errors.New("type assertion .([]byte) failed")
+
+	}
+
+	var i interface{}
+
+	e := json.Unmarshal(source, &i)
+
+	if e != nil {
+
+		return e
+
+	}
+
+	*p, ok = i.(map[string]interface{})
+
+	if !ok {
+
+		return errors.New("type assertion .(map[string]interface{}) failed")
+
+	}
+
+	return nil
+
+}